Sceptile-Good moveset, Timid Personality is good, with EVs of 252 Special Attack, 252 Speed, and 6 HP. Attach Leftovers or Petaya Berry.
Alakazam-Pretty standard. Basically, everything that I said for Sceptile as far as personality, EVs, and attachments would apply here too.
Starmie-Not bad, Timid Personality, EVs: 252 Spd, 252 Sp Att, 6 HP. Attach Leftovers.
Skarmory-Pretty good, Rest would work better then Steel Wing. Even though it gets STAB, it really isn't all that effective. Impish Personality, EVs: 252 Special Defense, 129 HP, 129 Attack. Again, go with Leftovers.
For the other two Pokémon, I guess that Crobat and Slaking would be the best choices.
Slaking-Moveset is a pretty standard physical sweeper moveset. Jolly Personality, EVs: 252 Attack, 252 Speed, 6 HP will work fine. Attach either Leftovers or Choice Band.
Crobat-Nice hazing toxishuffler moveset. Jolly Personality, EVs: 252 HP, 129 Defense, 129 Special Defense
Overall: All of your movesets are very good. However, it is pretty dangerous having 3x weaknesses on your team. Especially when you have them against common types. This team would be very vulnerable to Elecrtic moves, such as Thunderbolt, which is a very common move, there is usually at least one T-Bolter on every team. Bug moves, like Heracross' Megahorn could also do a lot of damage. So basically, the 3x weaknesses are the biggest concern with this team.