It took me 20 years to a) accumulate enough cash to buy a Hasselblad system and b) have the right opportunity come along. When I had the cash and opportunity, I bought. I haven't had a second thought about it. It's a pleasure to use and makes excellent negatives. (I could make better images, but that's not the point here.) If I sold the system today (503cx, 80, 120, 50, prism finder) I probably could get close to what I paid for it.
I use mine with a Vivitar 285 flash, and usually meter with a spot meter. I don't use it for action scenes, and have reflexes much too slow to have recorded my high-speed kids when they were small. That's what 35mm is for in my experience.
There is a bit of a learning curve, but so is there with any new camera or system. Given the number of fashion photos taken with Hasselblads over the years, you'll probably learn to hand-hold it with little trouble. Yes, get the CF lenses. A 500C/M in good condition is a good choice, unless you want a winder. The winders aren't all that fast, and the EL/ELM models only advanced at 1 frame per second, so there's no gigantic advantage there. A pistol grip is very helpful. Focusing quickly is a little difficult, but the acute-matte screens coupled with a prism finder make it much easier than without.
Good luck! I know it's not an easy decision, but you won't get burned if you decide to re-sell it.