wow bro...youv'e got a lot of searching to do! Have you used the search engine on this site. It's great, any possible question u have will probably be answered on the search engine.
1. dbol is very androgenic and has a doulbe bond between carbon #4 and #5 so yes, hair loss is possible with dbol.
2. There are many precautions u can take for hair loss such as proscar, propecia, nizoral shampoo.
3. Dont look at your dads hair to see if u are going to lose hair as well.
4. Genetically speaking, look at your mothers father and that is what your hair will look like (simple genetics)
5. I dont think you want to do a deca/dbol only cycle. (with your goals in mind) a better cycle would be something less androgenic and less harsh.
6. It seems as though youv'e got a lot of research to do on usage. (hence the search engine above)
7. One cycle will not just make you big. LOL.
8. Feel free to P.M. me if youv'e got any more questions.