Okay...for status gunning you rarely need recoil+3 skill as +2 will be sufficiant for most things.
Id use a different gun though, seeing as that combo is pretty weak in itself, sure status is nice but damage is nice to have as insurance. Also seeing as your gun has no shield I highly
recommend evade seeing as you cant block and your defence is very low.
I use stuff like these when I support:http://mhtri.comeze.com/armor.html?0_1v_1S.1R_1h.1S.1R_1h_1R.1R_p.1F.1S
Its not amazing, but fairly easy to make and served me well for many HR's and still use it today.
As for gun I either use:
Rathling+ frame,Chaos Wing and peco/needler barrel (needler gives pierce shots and wyv fire lv 1)
This setup gives (with Load up) 3 exhaust, 3 lv1 paras, 3 Lv2 paras, 2 shots of Lv2 sleep, 3 recov lv2 shots and natural low recoil. It can also hold Dragon S and wyv fire, which is nice to have with its good attk power.
or Bari frame, Chaos wing and needler.
Standard Sleepbombing setup holding (with load up): 5 pierce lv 2's (boosted by +20% natural affinity), 3 Wyv fire Lv1's, 3 sleep lv 1's, 4 sleep lv 2's, 3 recov shot lv 2's, 3 lv 2 paras and 3 exhaust.
Question 1: Load is is not needed but it help alot when you gun, you will be suprised by how useful it is.
Question 2: Carry more than just elemental shots, carry all the things needed to combine into that ammo type (like fire herbs+huskberry) as well as a few pierce shots. You shouldnt run out if you pack properly.