I did this once, with a one man capsule. 1.25m parts, lots of stages, lots of aerospikes. Around the whole thing, I put another asparagus layer of small tanks & tiny engines, idea with those was that I had science parts, parachutes, landing legs and things like that on them, idea ofc being that they get dropped very soon after liftoff. As for dropping parachutes, did you have them on decouplers? Sepratrons alone can't yank them off your rocket, you need to decouple the chutes first, separating rockets are there just to toss them out of the way. edit - re-read your post, you had decouplers. but it should work though.