Looking at your avatar, you are already quite lean. Given your body type, you will be able to shed any unwanted fat that you gain along the way quickly. I'm willing to bet that you find it hard to eat enough food to grow, so I would suggest that you drink it.
Augment your diet with a shake or two a day consisting of 1-1 1/2 cups of oats, 1 cup of blueberries, half of a large tub of cottage cheese, a scoop of protein powder, and a giant tablespoon full of natural peanut butter. Pound two a day, if you start getting too fat, reduce the size or drop one completely. Pound a lot of olive oil down your neck as well and start eating fattier meat. You just have to up your calories and you'll do fine.
Keep in mind, that you haven't struggled with staying lean, you've struggled with adding mass. So, don't worry about getting a little softer just so long as you're getting bigger, you'll be able to shed that with some smart training and an appropriate diet when the time comes.
As for shoulders, long-limbed guys like your self generally need to do more isolation work than those with shorter levers to cap off the delts, so just make sure that you're hitting lateral variations with lots of volume and different rep ranges. Also, keep in mind that you can hit delts several times a week just so long as you're smart about it.
You can hit calves two or three times a week as well. Just be sure not to bounce too much, as that's just relying on the elasticity of the achilles tendon largely. Pause for two seconds in the stretch position and two at the top for most of your sets.
As to the AAS advice, I'll leave that for someone with actual first-hand experience.
Best of luck.