I have a pair of the TF10s and Shure 535. I have used both extensively while running, hiking, basketball, working out, you name it.
The TF10s are not as bad as they are made out to be fit wise, you can make it work, it just takes more time for certain people with smaller ears. Just wear them behind the ear and it would be fine. Considering the bargain they are going for, I think it's a good investment. They stay secure while I run, and they sound great. I wouldn't be worried about sweat damaging them honestly. I sweat a lot, way more than the average person, I have people tell me this all the time while playing basketball when they have to guard me, haha.
I have never had an issue with any IEM due to sweat, even for marathon sweats (over 2 or 3 hours). The Shures sometimes would have some shorting out issues due to the connection on the detachable cable, but that would only be like an hour or more into a sweat. After drying (or if I detached the cable and aired out the two ends), they would be fine.
In other words, my recommendation is for the TF10. If you are looking for a versatile IEM, this is a great value. It's cheap enough that I wouldn't be panicking about damaging them anyway, which I assure you that you wont. The cable is the perfect length too, not too long that it gets in the way. I clip my Sansa clip to my waist band and it's secure and the perfect length.
Also, I disagree that the highs are harsh, I think they are perfect. It sounds like you care about fidelity, or you wouldn't be stating your top two choices as a TF10 and a westone 3. I'd recommend getting something that will please you sonically as well as functionally, rather than be overly concerned about damaging a higher end product.