Against a list like that you need to be hyper aware of his threat ranges, and what can Double Move/Assault.
Hive Guard have a 36" range, and they dont want to move and shoot. Generally they are hiding in the back field, behind a Ruin. You do not want to put 1 boat in that threat range, because it will be dead.
However, having multiple Raiders touching Dense, all within that threat range (getting ready for a next-turn-charge) is a viable tactic. Also, Reavers can move 18"+2"Movement Drug+Advance 8"+Charge (7" average)+Cult of Strife +1" = 36". The same range as Hive Guard.
Against the Stealers, you need to be hyper aware of where they are. Stealers are very fast, but are also quite costly and dont do THAT much damage. They need to get in range of an ideal target, and Raiders are not Ideal Targets. Positioning and screening will be your primary response to them (Court of the Archon, Wracks generally).
In general we continue to do our standard tactic, positioning to trade up. Nids are not very point efficient, so getting a few units of Wyches/Incubi into combat will generally swing things in our favor. We have great secondaries that will force the opponent to come to us (Herd, ROD), so we should be able to set up those favorable trades.
Be aware of the opponents threat range, and stay outside of it as much as possible. Abuse Dense Terrain as much as possible.
Good luck buddy!