We're using Discourse:
1. The following URL is parsed incorrectly when converted to a tile within a post
That's the website owner's fault. If you view the source of that link, you'll see some meta tags do indeed say "null | Samsung US".
2. Correcting an error in the title of a post grants the '
Wiki Editor' badge.
If you're referring to this recent post, that's because it is a wiki post (by default for tips/trick categories) 
Easy way to earn the badge though!
3. The post composition interface needs a button for
undoandcenter-justify embedded image(which are features I have seen on some other forums)
Good idea, looks like it's already been suggested:
Not sure if text justification may be one since there isn't a standard for that in Markdown, which is the primary editor. I don't think Discourse would want to encourage rich text editing with custom fonts, text sizes and colours, which reminds me of traditional forums. 
4. The forum indexes show a view count for each post, but counts are not displayed on the users activity page.
It sure does for the Topics section, which makes sense as it's their topic:
For post activity, I don't see much value in knowing how popular it is and would add a bit of clutter.
That's just my opinion. You could suggest this to Discourse developers, unless I've misunderstood #4?
5. Changing the forum theme from light to dark in user preferences does not work in Microsoft Edge .
Edge will soon be based on Chromium, maybe ported to Linux too so... we could wait this one out due to other priorities, unless there's significant demand.