1) So apache is running with your username? The only thing to remember is that apache now has the same permissions you do - if you could delete any important data with your login, so too can apache when set up this way. It would be better to put apache back the way it was, give the group write access to the files you need to edit, and make yourself a member of that group instead.
2) I haven't seen any stability problems on my machine, but what this usually means is that it's not nearly as well-tested as apache1 with PHP, or that there are still known bugs to work out. If you feel comfortable testing it, go ahead, but be prepared to switch to apache1 if any problems occur for you.