*Changing screen name, avatar or description is done so few that it can be done on a computer =)
*About the DM Tab, i think both in the same tab is best. I dont think people DM that much either.
*Picture cache is a good idea!

I also got 2 bugs to report:

One you already mentioned yourself: The link clicking doesn't work that well.

The other one is that most symbols don't show up.
For example, if i tweet :
"Hello, I <3 Tweego"

It shows up in tweego like this:
"Hello, I"
(So everything after the heart is also gone)

Further i wanted to say you guys did a really nice job already, Tweego Rocks!
Keep up the good work!