[Wasabista]

OK here we go...

1/ Ooki na and Ookii mean the same thing. Same with chiisa na/chiisai.

2/Yeah, that's a lot. Sorry. A good grammar book will sort this out. Those topics cover several chapters in Teach Yourself Japanese, among others.

3/ How do you say "too"? As in "I have too many papers". I read song lyrics, and I think I could guess that it is "sugi" but I'm not really sure.

Shinbun wa oosugiru: I have/there are too many newspapers. Actually "ooi" can mean the same thing depending on context.

4/Yori is used for comparison. Tokyo wa Maebashi yori ookii. Tokyo is bigger than Maebashi.

5/ "kara" has many uses. "Da kara" means "because." But don't try using it till you've mastered the phrase order.

6/ See above. Japanese is left-branching which means that to say "I drink because I have stress" you say "stress-exists-because-drink."

7/ and 8/ : Big topics, sorry.

9/ "As I expected"

10/ Depends on context. Libraries of linguistics papers have been written on this topic.