1. I think 'besides' would work quite nicely.
2. That would be good as well, though it's not too bad in its present form as well... perhaps even better to have that distinction from present to past. It does make more sense to go as chronological as you can, however.
3. I don't think 'at present' or 'presently' would make the stanza flow there. =/
Replacing the second one with "then" may not be too bad. Up to you there.
4. That's fine.
Not at all! I am glad to see you taking steps towards it all, but it wouldn't have been a bad thing if you hadn't.