Lots of yeast problems

Okay so I posted a few days ago about my Emma's Ale tasting sour-apple-ish and figured it was because my ferment temps got too hot (even though the rest of my batches have come out fine so far).

So my milk stout has been in the primary for 4 weeks now. I go to take a FG reading at it's still at 1.030!

I used SafeAle on both batches. I'm thinking I should have used 2 packets each. The Emma's ale FG was 1.020 which is also high. Maybe the fruity taste is because it isn't finished yet? Is it okay to re-pitch 4 weeks after brewing?

FYI I did shake the crap out of them every few days for the first two weeks to try to keep everything going.

A milk stout (generally containing lactose, which is unfermentable) finishing at 1.030 isn't uncommon. A pound of lactose in 5 gallons will add about .007 to the FG.