Well, I have a few ideas. I was originally considering to post this as a reply to bchandark's thread, "Confirmation Dialogs, other suggestions", but it seemed silly to confine so many different suggestions to a reply.*
I'd like to say that I agree with all the suggestions in the mentioned thread, and apologies in advance for any typos: I'm not good at spotting them myself.


Other Useful Threads
Confirmation Dialogs, other suggestions
Forum Suggestion: Edit
FORUM: My posts feature
Forum:Search function
New Erasers!

In-Game
-An Elements Search Box on the menu. Maybe the icon for the folder would look something like this:



Opening the folder would pop up a small box where the elements of that category would usually appear. Type in the name of any element (spelt exactly the same) and click a small "Ok" button at its side to have the searched element your primary element. If spelt incorrectly or the element doesn't exist, the box will be tinted Red. If the element is found in the databases, the box will be tinted Green.

-Either a Stars rating system of 0-5 or some way of seeing how others have voted other than the indiscriminate green and red bars. Perhaps hovering over them will display the number of votes? i.e. Positive Votes: 67, Negative Votes: 2.

-Shift (or any other non-interfering button) + Middle-click on empty space to make secondary element Wall Eraser.

-Middle-click on wall to make the wall your primary element.

-4-letter Names for each wall. So they can be hovered over with correct information and for easy reference on the Forums.

-Hovering over a wall will show information as though it were an element. Pressure would only be shown if it allowed air, otherwise the pressure would be listed as N/A, like Temperature. For example:
DCTR (Detector), Pressure: -0.07, Temp: N/A

-New Folder consisting of Erasers. There are currently only two but who knows how many might pop up as more elements and features are added and updated? Also useful for quick finding.

-Select and Move Tool. Perhaps the button could be selected from the elements menu, situated in its own folder or in the same Question Mark folder as the Elements Search Box (if implemented). Would require the same cursor as when depositing elements and brush size would be changeable.
Hold down key click over any non-fixed elements i.e. Powders, Liquids, Gases etc...
Drag cursor while key click held to move elements within the brush size's area.
All particles in the brush area would be attracted toward the centre of the brush and, in the process, mixed around. For example, if Salt and Water are Selected and Moved, Saltwater will probably be present by the end. Therefore, its use would probably more for quick "smelting" or creating mixed crystals, rather and Selecting and Moving, to be honest.
Even better would be if Ctrl+Drag+Click would work with Select&Move, too!

-Extended Credits. An option to view a detailed list of credits for those who want to see whoever created/fixed/updated exactly what, when they did it and whoever their TPT accounts are. Would also be nice as a bit of history of the game's gradual progression.


Forum
-Detailed Profile. You can enter data such as "Timezone", "First Language" to even "Hobbies", depending on your desire to share information!

-Profile Statistics. Along with profile information, statistics relating to the account. For example:
Rank: Administrator/Moderator/User
Join Date: 21st December 2012
Topics Created: 1337
Post Count: 9001
Simulations Published: 42
Overall Positive Votes: 294
Overall Negative Votes: 89
Forum Reputation: 18
...and etc...

-Inter-Post Info. Some User statistics are shown, small, in a margin, such as:
Rank
Join Date
Post Count
Forum Reputation
Just for easy recognition or judgement. Say, a player with incredibly low reputation is caught spamming by a Moderator, they will know immediately whether to warn/reprimand or just ban!

-Ability to scroll through the posts of users via their Profile and view the threads in which they've posted.

-Ability to edit posts which have been replied to. Currently, we lose the ability to edit!**

-1Up and 1Down buttons on posts to evaluate their post: Was it useful? Was it informative? Or was it rude? Or unhelpful/pointless?
1-Up would indicate a "thank you for the post" and would appear in their profile as a positive point to their "Forum Reputation". 1-Down would indicate "no thank you for the post" and would decrease their Reputation. This would certainly give people an incentive to post useful comments rather than nasty or off-topic posts!


Keybindings
-Ctrl+Y - Redo
-Ctrl+O - Open "My Own" simulations interface
-Ctrl+F - Elements Search Box

General
-Confirmation dialog for positively and negatively evaluating others' simulations.

-"Cancel Vote" option, once evaluated another's simulation, in case of an update to the simulation which has changed your mind, or really whatever the reason!

-F# or an on-screen button to open up a database of elements with information. For example:
Element: LN2/Liquid Nitrogen
Description: Very cold. Disappears at higher temperatures. Can be used to cool electronics or appliances near heat sources indefinitely.
Spawn Temp: -205.00 C
Room Temp State: Liquid
Changes of State: NICE/Nitrogen Ice @ -210.00 C, Disappear @ ~-200.00 C
Version Added: <insert version in which LN2 was added>
Creator: <insert creator of LN2>
Would be helpful to record the properties of every element for a newcomer and gives the chance for a more detailed description than that which can be written just above its selection button!

-F# or an on-screen button to view the instructions that appeared at the start.

-Another way of sorting simulation order: By Category (Good for checking for related simulations using pre-set categories rather than relying on the accuracy of the creator's tags)
Before publishing your simulation, you will have to select a Category ranging from things like "Electronics", "Nuclear", "Stickman Level", "Explosive", etc... and "Misc". All current simulations would be automatically placed under the category of Misc. It will be up to the creator to change categories on their next save.

-Another way of sorting simulation order: By Balance (Not particularly in demand but would be a nice feature)
Balance would be based on {Positive Votes-Negative Votes). To see the most refined works! (Most approvals yet least disapprovals)

Public Suggestions
-Donations Box ~ Lolzy
A way of donating money as aid on developing projects or to help extend the Powder Toy Wiki, which incidentally requires donations. Perhaps another Tab on the site could be made (next to Download, Forum, Browse, etc...) named "Donations" where some sort of donation system could be resident, or the Wiki could have a Donations page which would be promoted by this website (I am almost 100% sure that there is a way to set up a Donations Scheme on wikis). Somehow, a list of previous donators would be shown, with their Username/IP Address and Amount Donated displayed.

*I don't know exactly how to code all these in so I may have suggested some truly insane ideas. Sorry if that's so!
**Seems to have been resolved!

Thanks!


I'll try and make it easier to read. I agree with you: It does kinda look like an off-putting, big block of text.

Anything to polish the game and website helps, however small, no?

^ I've added that to the first post because I agree

But I don't really understand how it would work. Can you explain?