I currently have a javazon at the end on NM with a 20 LF, 20 valk, and some in CS for bosses. The few Lightning immunes I've met are a bit of pain and I leave them to my capable merc and valk but in hell it might not be so easy. Should I go with a plague javelin or a bow on switch when it comes to hell? I'm playing sp so infinity and other crazy items are not going to happen.

Bow for sure. Freezing arrow. Even if does low dmg they get frozen so your merc can kill easier.

Cs, light fury, light res wand, 20 valk, obedience treachery merc.

Should get you through hell after farming some decent gear. I wouldn’t respec

Just jab as long as not PI.
I like hybrid bow/LF tho, so like other guy said FA + MA works well but you have to add dex (usually gets you MB on jav side tho).

LF strong enough even for hell even if just 20LF + 20CS. Rest could go to bow aide + valk. Put lawbringer on A5 Merc. Between Merc and valk you have solid tanks.

Run w/jav, if scary enemy switch to bow and use FA. Decrep procs from LB. Merc and valk tank. You can finish with bow GA/MA/MS or even strafe if safe or CS or LF. Fun, versatile build IMP and can handle all hell area. Not the fastest, but keeps you safe in hell on HC P8 until infinity enigma etx

Thanks everyone. I'm going to spend the rest of NM doing a bunch of Baal, Chaos, and Meph runs looking for

1) a base for harmony
2) Two bases for treachery (me and my merc)
3) Titans revenge
4) Maybe a base for Lawbringer (If I go with act 5 merc)

After lots and lots of meph runs I found my titans and also a buriza for switch.

I currently have 2-3 in FA. Should I try to max FA or just leave it low level? I have nothing in multi or strafe. The only 'spare' points I have are 6 in penetrate and 6 pierce.