I have thought of no less than three Dungeons & Dragons 5th edition spell hacks. Is there anywhere on the site I can post these?
This is a Q&A site, we don't have a blog or other places to post work or statements. May I suggest one of the forum sites, see I've been told my question is better suited to a forum, but where should I go?, or a blog.
While this isn't a place to post them for discussion, you can post a question to verify that your "hack", or interpretation, is correct.
Yes, in the main site.
Adhere to the Q&A format. Post a question that poses a problem that your hack solves, then post an answer yourself.
Q: X spell seems too weak. Is there a scenario where this spell could be useful?
A: Yes, [explanation]...
Actually StackExchange encourage sharing your expertise in this way. You can even gain reputation quicker by doing that! (good question+good answer)
Remember, though, that your question should still follow the rules!