I want to ask about grammar items.......

I found some useful websites for you.
For 1) Conditional sentences: (This website not only explains you the types of conditional sentences, it also has many exercises waiting you to do. I think it is worth to try it out. ^_^)
http://www.ego4u.com/en/cram-up/grammar/conditional-sentences

2) Reported Speech
http://www.ego4u.com/en/cram-up/grammar/reported-speech

3) Would rather...(than...)and prefer...to...
Sorry couldn't find it yet.

4) Too much,too many,
http://www.ego4u.com/en/cram-up/vocabulary/much-many/exercises?04

Little/few
http://www.ego4u.com/en/cram-up/vocabulary/little-few/exercises?05

5) Comparative and Superlative adverbs
Sorry couldn't find it, too.

But overall, this is a good website which contains numerous grammar points. I hope it is helpful to you.

http://www.ego4u.com/en/cram-up/grammar