No other solution other than up sizing the conduit. Per the NEC, 1/2" Liquidtight is good for (6) #10 but there is some de-rating involved when using more than 3 current carrying conductors in one raceway.
I would suggest buying a piece of 3/4 Liquidtight. If you can, ream out the knockout with...
Yes, you can put 120v and 240v in the same junction box. There is a code section specific to switches. If the voltage difference is less than 300v you can have the switches in the same box.
A. Snap switches must not be grouped or ganged in enclosures with other snap switches, receptacles, or...
Being an Electrician, everyone I know uses Klein. I use these:
http://www.service.kleintools.com/Tools/PRD/Category/Klein-Kurve%20Wire%20Strippers/Cutters%20-%20Solid%20&%20Stranded%20Wires%20STRIPPERS-WIRESTRIP-SLDSTRKK/Product/11055