First BIAB, marris otter/galaxy smash, how does the recipe look?

I'm interested in doing a BIAB SMASH-style to keep things simple. I picked Marris Otter for my malt and Galaxy for my hop. Going 2.5 gallons because I only have a 5 gallon brewpot, looking at a single pot, no sparge style BIAB.

Here's what I have so far:

6 lbs Marris Otter
.5 oz Galaxy (60 min)
.5 oz Galaxy (20 min)
.5 oz Galaxy (10 min)
.5 oz Galaxy (0 min)

Safale US-05

1 tsp Irish moss (40 min)

Pre-boil volume: Here's the first spot things get interesting
Hopville says 2.88 gallons which I know isn't right
Beersmith says 3.88 gallons
"Brew in a bag Summary" @ Brew Geeks: 4.1 gal (2.5 gal (batch size) + 1 gal (boil off per 60 min) + .6 gal (grain absorption for 6 pounds)

I'm thinking 4.1 gallon will work for my first attempt.
152 F mash temp
60 min mash time

60 min boil

Brew Smith sez: 1.056-1.075 OG, 1.012 FG
IBU: 89

Do these numbers look right? I'm shooting for an IPA (hell a drinkable beer would great at this point) but 89 seems a little high.

Also, Beersmith is assuming 65%, is that reachable for first time BIAB?

Any help is appreciated.

89 does look a little high, but otherwise it looks solid.

My biab came in at about 70% efficiency with a 1 gallon sparge, so you may be good with a 65% estimation.

What are the AAU's on your Galaxy?

Oh I am jealous. I did a Galaxy SMaSH last spring and went to repeat it a few weeks ago and can't find Galaxy now. I would push the last three additions off 5 minutes to lower the IBUS and still get a nice Galaxy kick. I wish it were mine!

@maltoftheearth If I'm doing the calculations correctly, 7% (.5 (the oz.s) * 14 (alpha acid of Galaxy))
@Early8 That's good to find out, the few Galaxy beers I've had I've really liked.