Lockbutton, speakers and mutebutton

Hey i just got a iPhone 2g very cheap, but have some problems with it.

1. Lock /sleep button dont work.

2. Silent button is broken, so its just vibrating when someone calls me

3. Headphone jack plugin is pushed inside the phone, so the metalthing dont fit it.

4. Speakers got poor quality

This sounds like hardware problems right?

I was thinking of buying parts from ifixit or other sites and fix it myself.

Could you guys give me link to the right products so solve these problems? (im not 100% sure if the products i looked at is the right one)

Thanks in advance!