Speed boost, if combined with a low base speed offers so many desicions. We could have it outspeed most of the metagame at +2 (Barring High speed scarfers) but at +1 if you pick the wrong coverage it could be sereverly maimed by a hypothetical latios or terrakion. Both of which will still threaten you. Maybe even a scrafty like speed stat, this would mean that even at +2 could be outsped by scarfers and high speed pokemon. This would mean that even with speed boost it could have viability with +spe boosting moves.
If you opt for protect you miss out on a coverage move and could be walled. I'm going to offer a hypothetical situation where you sucsessfully switched into a Deoxsys-D spikes and they have a heatran and a latios in the wings. You have Focus blast (Most powerful fighting coverage specially) along with Megahorn and psychic. Heatran is bulky enough to survive a focus blast (not to mention a miss) and latias can maim you with a draco meteor (SR + LO + Meteor = Sweep over)
A four attacks set with life orb (Maybe even expert belt) is very threatening with correct prediction a fire or ground coverage attack or bug,psy,fire,ground coverage would be incredible painful hitting a lot of the meta for super effective coverage, but without correct it is threatened and killed the first few turns become incredibly risky. Sucker Punch can be a dead stop to a set like one of these, and if combined with pursuit produced all sorts of risky mind games. But even with four moves you will get walled by something. more than likely.
A boosting set could play very well, but would require the removal of scarfers and still with only three moves you could likely power through alot of the meta, but still faces heavy opposition to switch in. A stealth rock weakness means that you can't attempt to set up with impunity and switch out if your opponent makes the right prediction. Without a grass coverage move (Which would likely never be used) and if not life orb then quagsire could be a really solid check. Just to prove it wouldn't be another blaziken heres some calcs. (And don't say quagsire is obscure bad pokemon, the beautiful quagsire is actually very viable in OU)
252 +modest base 130 Special attack STAB bugbuzz vs. 252/252* careful quagsire [153 (39%) -180 (46%)]