I did a solo self found on bnet. I ended up maxing lightning sentry, death sentry, fire blast.
5-10 points in BoS
All your normal 1 point wonders aswell.
Ended up with about +6 skills
It was easy to clear pindle, Andy, shenk.
Nillik and countess I would throw down lightning sentry from "outside" wait a few seconds then throw down a few death sentry to wipe the whole mob.
It was super chill and cheap
As far a solo progression I'd reccomend dual spec and lower resist wand. I got all the way into act 5 hell before I caved and got wps.
I would generally not use a merc unless I needed it for the melee damage.