I personally don't have it because I usually launch enemies with Cut Down or Air combo launch

Rocket Punch: [Optional]. This skill is great in PvP, not so much Rappelz Rupees in PvE. It can stun enemies...

Nosel Tuning: [Optional]. Get this for more damage when using Rocket Punch!

Relaunch: [Optional]. Meh, this skill is optional. I personally don't have it because I usually launch enemies with Cut Down or Air combo launch, but it's your choice.

Useful Combos: Air Combo Launch -> Aerial Frenzy -> Cut Down -> Aerial Frenzy -> Repeat.

Training Areas: Level 1 ~ 10 - Do all the quests possible as they provide nice exp and good rewards. Mission Maps: Big Bad Wolf and possibly Vega with a party. Level 11 ~ 20 - Tutu and Toto and around 19, try Captain White Tooth with a party.

Helpful Hint - Mission with a party, if not, go through F1~F4 and skip boss. Also, when you're doing Tutu or Toto, stand exactly where he is. He can't attack you. However, this requires good controlling and the small boss is really annoying.

Yes, accelerator tuning increases damage of heat seeking missile. 2nd skill: MRLS (Multiple Rocket Launching System)

Summons a LAROM MRL vehicle that at level 1, fires 10 rockets at once in different directions, although quite obvious that accuracy is extremely compromised. At level 5, increases damage and rocket output to 30 rockets being fired. Accelerator tuning increases damage.