WoF can be used to solo in SP. If your definition of swell is "kills easily", then no it's not. She won't be taking on hell solo in much over a two player game without a lot of difficulty. It is a fun skill to use, however, and in a few areas of the game does great. Go into building her with the idea of having fun and desiring to overcome a challenge most say isn't worth it and a fire trapper will fill what you're looking for.
The idea with WoF is to keep targets continually on top of a flame. The Nextdelay issue can be worked around. Notice when you lay the traps how they are firing. If they fire at the same time, space them out enough to separate the waves rather than stacking the traps. The flames spread out in a diamond pattern. Try to keep targets at the corners of the diamonds. That tends to let them fry for a bit longer.
As Bigeyed stated, you don't have the ready made immunity solution that lightning trappers have with fire blast. If you want to go the pure trapper route, you'll be looking at something along the lines of:
20 Fireblast
20 WoF
18 shock web
20 charged bolt sentry
That will give you CBS as an FI solution. Shock web isn't an FI solution imo. It suffers even worse than WoF from the Nextdelay problem. CBS works nicely as it also gains a damage synergy from Fire Blast. The points in Shock web won't give a damage synergy to any of your skills, but they are needed to make CBS usable. You could cut 9 pts from there if you wanted. It would weaken CBS considerably however. If you get death sentry and blade fury as well, you've got 82 pts put into the trap tree. Not enough pts left to get a decent level shadow. I'd suggest grabbing a single pt into a shadow (master would be my preference) strictly to use as a diversion. She won't be a lot of good for much else unless you have a huge amount of +shadow skills.
In the end, I say build her. The important results of any game are having fun and feeling satisfied with accomplishing what you've set out to do.
jrichard
edit: clarity
The idea with WoF is to keep targets continually on top of a flame. The Nextdelay issue can be worked around. Notice when you lay the traps how they are firing. If they fire at the same time, space them out enough to separate the waves rather than stacking the traps. The flames spread out in a diamond pattern. Try to keep targets at the corners of the diamonds. That tends to let them fry for a bit longer.
As Bigeyed stated, you don't have the ready made immunity solution that lightning trappers have with fire blast. If you want to go the pure trapper route, you'll be looking at something along the lines of:
20 Fireblast
20 WoF
18 shock web
20 charged bolt sentry
That will give you CBS as an FI solution. Shock web isn't an FI solution imo. It suffers even worse than WoF from the Nextdelay problem. CBS works nicely as it also gains a damage synergy from Fire Blast. The points in Shock web won't give a damage synergy to any of your skills, but they are needed to make CBS usable. You could cut 9 pts from there if you wanted. It would weaken CBS considerably however. If you get death sentry and blade fury as well, you've got 82 pts put into the trap tree. Not enough pts left to get a decent level shadow. I'd suggest grabbing a single pt into a shadow (master would be my preference) strictly to use as a diversion. She won't be a lot of good for much else unless you have a huge amount of +shadow skills.
In the end, I say build her. The important results of any game are having fun and feeling satisfied with accomplishing what you've set out to do.
jrichard
edit: clarity