All-grain 2 gallon batch with grain bag: Questions

I have a little 3 gallon carboy for small batches and wanted to brew up a small batch of Belgian Blonde. I figure if I do only a 2 gallon batch I can get all my sugars from grain. I don't have an all grain setup but I do partial mashes. I have a big grain bag which I would use for this. I usually do partial mashes using 2-2.5 lbs of grain for 4 gallon batches, so this wouldn't be too much more than that at under 4 lbs total.

Here is my preliminary recipe:
OG = 1.061
3.0 lbs Pilsner malt (70.6%)
0.5 lbs Wheat malt (11.8%)
2oz Belgian Aromatic (2.9%)
2oz Caravienne (2.9%)
0.5 lbs Cane Sugar (11.8%)
------
0.5oz Hallertauer (3.6%AA) @ 60 minutes
------
WLP500 or Wyeast 1214
------
Mashing at ~149 for 60 minutes at 1.5qts/lb. (I'm predicting ~70% efficiency for my ProMash calculations, if I end up getting better efficiency I'll just add less Cane Sugar). Sparge with enough water to have 3 gallons before the boil (promash tells me I would end with ~2.10 gallons). Boil for 90 minutes.

So my question is, since I've never done an all grain before, other than making sure I sparge with enough water to get my pre-boil gravity, is there really any difference here than doing a partial mash? Does it seem like I have this process pretty well covered or are there any tips anyone can give me (recipe or process). If you're scratching your head at "why only 2 gallons" just go with it. I don't mind small batches to experiment

Thanks for any help.

2 gallons is just fine, I just finished a 3 gallon batch of dunkelweizen a little while ago. If you're using a 3 gallon carboy, go ahead and bump up your volume to 3 gal going into the fermentor. There should be enough room for it in there as well as your krauzen (use blowoff if needed). That way, after the yeast and trub settle, you'll end up with closer to 2.5 gallons in bottles. If you start with 2 gallons going in, you'll probably only end up with a little more than 1.5 gal at the end of fermentation.

Otherwise everything else looks pretty good. Personally I'd go with a slightly higher mash temp, probably in the 152 153 area for a little more body. Your cane sugar should take care of your abv, but if you mash too low you'll lose body and it might come out too thin and dry. Since it's only a small batch however, give it a go and see what happens. My best learned lessons were from my brewing, not from forums