for your 1st question. Use 1 RAW. That's all i can say. Then go to photomatix > automate > single file conversion > tick "from low to high dynamic range" with radiance rgb. Then look for your file. then click ok.

Hmmm... Definitely will be different. If im not wrong, pic two will be darker at some areas. while pic 1 will have a more balanced shot. But still i cant be completely sure. Why not take a time out experiment it yourself?

But' ill go for method 1. Then bring to photoshop for further processing

Good luck.

have you tone mapped the .hdr file? You have to tone map the files 1st then only convert them to .tif so that you can view them or further enhance them.