Milk Chocolate Stout Summary 1st AG

So six weeks ago I brewed a northern brewer milk Chocolate stout. Tapped it yesterday and it is delicious! My wife is a big cofee drinker and loves it. I am not as much of a cofee drinker and its still delicious.

Couple thinks I noticed and may want to tweek. First off here is my brew schdule

OG 1.060
FG 1.018
READY: 6 WEEKS

-- 1-2 weeks primary;
1-2 weeks secondary;
2 weeks corney key conditioning at room temp under 15 psi co2
MASH INGREDIENTS
-- 8 lbs Rahr 2-row pale
-- 0.75 lbs. Simpsons Chocolate Malt
-- 0.25 lbs. Simpsons Extra Dark Crystal
-- 0.25 lbs. Weyermann Dehusked CaraFa III
MASH SCHEDULE: SINGLE INFUSION
Sacch’ Rest: 152° F for 60 minutes
Mashout: 170° F for 10 minutes
BOIL ADDITIONS & TIMES
1 oz. Cluster (60 min)
1 lb Lactose (60 min)
.5 oz. Cluster (30 min)
PACKAGING ADDITIONS AT Time of Corney keg conditioning
4 oz. Chocolate extract

YEAST

WYEAST #1332 NORTHWEST ALE YEAST.
Fermented at about 70 degrees

Couple things I noticed.
1. OG was estimated to 1.049. So I was 11 points off my OG. Not sure what would have caused that

2. Head retention is nill. It foams up but all the head is gone after 30 seconds or so. What could I do different next time to increase that?

3. My wife loves the espresso backbite but I dont and I dont really taste the chocolate too much. If I was to brew this again what could I change to dial back the cofee flavor and dial up the chocolate flavor?

Other than that I consider this a success for my very first AG. I have a IPA fermenting right now as my 2nd batch!

I believe oatmeal would help with more head retention.

I was thinking of subing out the Weyermann Dehusked CaraFa III for something lighter. Is that whats probably lending the cofee flavor?

What about adding cocoa to the boil to jump the chocolate flavor up?

When adding oatmeal and cocoa do I need to adjust anything elese in the grain bill or are they considered non fermentable adjuncts?