So, for anyone who has played a similar build... did you resort to using a 10mm pistol or cowboy repeater, just to put you over til you find something truly awesome? Or stick to the character, and stab people a lot?
Rad Child helps a lot with an explosives build's survivability - I think when I went pure explosives I used whatever non-explosives weapons I found lying around in the early stages (decent explosives are scarce to say the least). In a meta-gaming sense now I think I would get to the Strip early via Red Rock Canyon (picking up Turbo there along the way) then hightail it to the Boomers, use the Turbo to get through their howitzer shots and pick up Thump-Thump - which should do respectable damage with the early Grunt perk. Also with the Boomers you then have your ammo supply so you should be able to manage most of the Mojave.