1. Ive heard so many songs today that have done this - plz man try and not intro the song with just a pad - it makes things sound pasty. Add some effects - best one? - fade it in if u have to.
2. The sweep i suppose thats being side-chained maybe lighten it up its super heavy , and doesnt fill in those spaces. My advice would be make it lighter - more fluff- And at some points maybe eq it to where those high frequencies are let off.
3. The melody was nice I must say - but maybe for those transitions - give em some more energy, and also make that ending a lot more memorable - its a bit abrupt.