ROTH only. I changed to 100% ROTH a few years back as soon as I realized it had become an option. I also only contribute the amount required to maximize the company match. There are better tax protected investment structures than a 401. You eluded to one in fact the Universal Life policy. I use that with a strategy called infinite banking and it has been a real winner.
RE: Junk bond funds (corporate bonds) in your 401K.