Partial Boil vs. Full Boil

[jjp36]

So I'm going to start brewing my 5th batch this weekend, and everything up to this point has come out pretty fantastic. I did i couple of hefe's and a stoudt so far. However my favorite style of beer is Belgians. Knowing this, my buddy picked me up a kit of the Dutch castle magic mini-mash kit from AHS for my birthday. The ingredients are listed below:

9 lbs Pale Liquid Extract (8.0 SRM) Extract 58.06 %
1 lbs Lyle's Golden Syrup (0.0 SRM) Extract 6.45 %
2 lbs 8.0 oz Pale Malt (2 Row) Bel (3.0 SRM) Grain 16.13 %
4.0 oz Biscuit Malt (23.0 SRM) Grain 1.61 %
4.0 oz Caramel Wheat Malt (46.0 SRM) Grain 1.61 %
4.0 oz Munich Malt (9.0 SRM) Grain 1.61 %
4.0 oz Special B Malt (180.0 SRM) Grain 1.61 %
2.00 oz Styrian Goldings [5.40 %] (60 min) Hops 25.5 IBU
0.50 oz Saaz [4.00 %] (15 min) Hops 2.3 IBU
0.50 oz Saaz [4.00 %] (5 min) Hops 0.9 IBU
0.25 oz Coriander Seed (Boil 15.0 min) Misc
0.25 oz Orange Peel, Sweet (Boil 15.0 min) Misc
0.50 oz Orange Peel, Bitter (Boil 5.0 min) Misc
2 lbs Candi Sugar, Clear (0.5 SRM) Sugar 12.90 %

I already have cultered up a yeast starter from a bottle of Victory V-12 that i plan to use. My question is this: The instruction that came with the kit assume that i do not have a large enough pot for a full boil, however i do (i have an 8.5 gallon SS brewpot). I know that doing a full boil would probably be much better (especially considering the chance for carmelization with that much sugar), however my question is will i need to change the amount of hops used because of different amount of utilization? Also, The instructions say to steep the grain in 2.5 gallons of water for 45 minutes. Is there any reason for that? Or would it be ok to steep the grains in the amount of boil water i plan to use (~6 gallons). Any feedback would be appreciated. I'm really looking forward to this beer

 

[A4J]

I would decrease the amount of hops to the following:
1.25 oz Styrian 60minutes
.25 oz Saaz, 15min
.25 oz Saaz, 5 min

I always steeped the specialty grains in 2.5G of water but I don't know if more water would adversely affect the brew.

 

[Nablis]

If you steep your grains in 6 gallons of water you will still get the flavor from the specialty grains but you won't get all the fermentables from the 2 row because the enzymes would be too diluted.

It would be good to steep in 1.5qts per lb of grain or anything close to that.