I don't know of anyway to change the size of the text. I'm assuming you mean the text that you're reading.
If you're using the default messenger I would suggest you try either Chomp or Handcent and see if that doesn't help you out.
Nothing you can do about the time thing. Even on calls it will say "1 hour ago" and such. Just the way it's made.
If I'm wrong on the time setting somebody correct me, I've never actually gone in there and looked for a setting for it, but I've checked out settings many times and I've never seen one. And :welcome: to the Droid Forums.