I have been on HRT for 81 days (so short I know), but defiantly developing hairy breasts, so if you are worried about that, it may happen. Unless, of course, you intervene with some form of hair removal.
My hair does grow back more slowly, not much more but a bit, no change on the face of course. My endo(helping MtF since 1971) said that for a long, long time (1-2 years) expect only slower/lighter growth, but that chest and back hair may turn to light fuzz instead of male hair, but that would take a while, and is very linked to your T/anti-androgen levels.
I really feel your pain on the body hair front, as it seems one of the biggest hurdles to my transition at this point. Electrolysis is so time consuming and expensive it is extremely daunting, and the laser I have had so far has only had moderate success, as I have dark hair, but very very olive skin(1/2 black, but very light).
I'm pretty much at the point where I'm looking at paying $65 an hour for a highly recommended thermologist.
I still have a very significant amount of beard hair, so I think I just need to bite the bullet, and have huge spots on my face at work, while paying a ridiculous amount of money to lie still for hours having an electrified needle shoved into my face. After an electrolysis appointment, for kicks, I like to go get a root canal with no anesthesia.

*sigh* glad that's over. Smooth skin is totally worth it. Plus, the hairier you are to start, the more you'll appreciate not having it. Gotta be glass half full, I suppose. Some days it feels like too much, but a girls gotta do what a girls gotta do.
Besides, what's getting rid of a bit of body hair when your looking to change your external genitalia?