Maybe an alternative route... bake lighting into vertex color. This would avoid bleeding, but would increase vertex count on lighting seams. Or perhaps check out https://www.scriptspot.com/3ds-max/scripts/polyunwrapper I know the developer is very responsive to requests/feedback.
http://www.ig.utexas.edu/eqdisplay/scripts/helicorder.htm?file=whtx_bhz.20130418.gif Interesting seismogram, you can clearly see the blast up in the top-right.
The you have to write your own material script and custom shader to get similar results. (you can look into the material files of Torchlight for reference)
it should be possible to add the flash light to a weapon but it will have to be scripted and I don't know how to go about this, maybe ask over at the UDK forums
I can't live without ZhCV_Polytools, https://www.highend3d.com/maya/script/zhcg_polytools-for-maya-54377 in my daily modeling routine, especially the "regularize" tools.
It is this what I am trying to recreate, but manually, without a script! At minute 5:38 Notice the "lenght" label attached to the handle. http://vimeo.com/78739167