Double Chocolate Stout

Alright, I am about to stumble into another brew session. I would love some critiquing and tips from the old pros. I still haven't figured out beersmith, so I guess I'll just do what I've been doing and see how the numbers match up later. AHS PM kit- recipe is:
3/4 lb Chocolate
1/4 lb Crystal 40L
1/8 lb Roasted Barley
1/8 lb Black patent
2 1/2 lb Maris Otter Pale Malt

5 lb dark liquid extract
1/2 lb Malto-Dextrin
AHS Alcochol boost

1 oz Galena Bittering hops
1 oz unsweeted Cocoa 5min pre flameout

I have been doing countertop partial mashes, no step mashing keeping around 154 for 45 minutes and then adding first wort to boil. Sparging with 5.5 qts, then adding second wort to boil. I am aiming for about a 4.5 gallon finished boil (26 qt pot). I can't quite figure out (in beersmith or otherwise) how to estimate the volume of water the grain will absorb. for example= 5.5 qts strike+ 5.5 qts sparge = 2.75 gal, but how much will I actually get into the brewpot. If I got 80% (or 2.2 gal) of the volume back, I should have 2.3 gallons of water boiling in the pot to get a 5 gallon boil. How do the other PMers go about figuring this?

Okay, strike water was 175, lowered my grainbag in- slowly prodding the whole time, still at 170!!! dropped in a couple of ice cubes, got to 154 in about 8 minutes. Other than possible tannin extraction, what problems could that cause?

I wish I named this thread "take a look at my general techniques"! I added Malto-Dextrin and AHS alcohol boost 10 min after the hops. If doing late extract addition, should that be done at same time as extract or early?

Stayed up till about 2am, oops. After racking to primary, ended up with exactly 4 gallons, added 1 gallon top off water that hadn't really cooled down. Hit my Est OG right on. Ended up pitching at about 90 degrees, but it was a big starter and I was falling asleep. Bubling away fine 6 hours later.

For my attempt at sparging this time, I ran a quart off & recirculated a few times. I the drained the cooler and added the first wort to already boiling 2 gallons. I then slowly added 2 qts to the grains, evenly pouring all over the bag until they were submerged, I then drained the cooler and repeated the process 2 more times. I know a starch test comes into play here, but I don't know what or how to do that. Any other pm'ers have a better/ different way?

Not getting much response in here, maybe I should ask in all grain/ pm.