Probably not, sounds more like troubles due to engine/your pc.
No. That's the game loading/streaming assets from the hard drive into RAM and VRAM. A lot of games do that, especially open world games. A SSD will minimize it
Indeed. This I can personally confirm. The engine is one issue for sure, but hardware definitely plays a part. I recently OC'd my CPU again (1Ghz OC) and got my SSD back from RMA and what a difference over my WD Caviar Black/no OC.
You really feel it in the cell transitions and the load times are nice and quick. (Not that they were terrible with the HDD.) With my SSD it's a slit second pause in game play as the cell loads but smoothly carries on once it does.