Agreeing with Heckler, neither Fast Shot nor BRoF should work with grenades - and I think they both work. At the moment, grenaders win thanks to grenade-spam.
Grenades win? Lies. Let's elaborate on that:
- molotov - lol, unusable
- frag - knockdown, yeah, but the damage is laughable - unusable
- plasma - knockdown removed, inflicts 30-40 dmg on a BA wearing target; the range is 15 hexes, you need 5 or more to get a dude with 200+hp, which already puts you inside the realm of jet, which is a bit shitty to get; now, let's assume the opponent starts running when you throw the first 2 from 6 hex distance. What happens? He's out of range until he's dead and since you both run with the same exact speed you CAN'T KILL HIM, EVER. That's what happens with 2ap/throw. Imagine it's 3ap/throw or 4ap/throw. Oh, and if the target happens to be a BG user he can run up to you and cap your sorry ass with a burst while you light yourself up with splash damage.
tl, dr version; what you both suggest is to make an additional weapon skill completely useless.
Oh, and what Heckler said doesn't even make sense. Yeah, grenades have all these drawbacks irl. They also have 15-50m realistic kill radius and, unlike firearms, offer almost 100% instant incapacitation of the enemy. Basically, a well thrown grenade can wipe out an entire fireteam. I don't remember any 2238 grenades doing that.
As far as sneak goes - introducing a global -75% until FOV appears (everybody is "in front" of you all the time) would do the trick. But with the entire "I failed to adapt so let's axe this thing" crowd whining at the top of their lungs such a sensible solution probably isn't going to pass.