Income and ship replacement. Pirate corps providing a safe...ish haven for ratting/missioning? Same-region market play? It seems like you'd either have to import ships ("Hi, can you freighter this to low sec? No trap, really!") or make them yourself. The best answer I can think of is "make friends" but the red-and-flashy set seem a little cagey. I'm feeling the pull to blow people up and go red-and-flashy myself but I'm a planner at heart and want to have a clue how I'm going to keep myself in ships.
arrhidaeus
It is very doable, even without a hauling alt, but you just need to be a little suicidal.
For starters, if you're a member of an influential pirate corp, you'll probably be able to rat/plex/mission in your corner of space in relative safety. Keep a good lookout for strangers in local and scan probes on your dscan and you'll be fine (or if you're insanely rich, fly an unprobeable strategic cruiser). You shouldn't need much more financial support than that unless you have a serious addiction to faction ships and complex mods.
As far as hauling goes, for most parts of space, yes a hauler alt is helpful. If you happen to live near Hek (like I do), which is a 0.5 trade hub with gates to low-sec, you can make a insta-warp from your undock, put some warp core stabs in your lows for good measure, and ninja-warp battleships out of the station literally all day in relative safety. This is how i do things, and I have no hauler alt, barring one that I've never trained that I occasionally use to haul small things in an Ibis with.
If you don't have ninja'ing as an option, an easier alternative to skilling up an alt on your same account with hauling skills, is to just train your alt to be able to fly a battleship of your choosing, and to have them fly it to your low-sec station. This only works well for T1 hulls though, but hopefully you'll have a corpmate that can spare some T2 frig/cruiser hulls in their hauler from time to time, and so long as you have a method of getting the BCs/BSs you want, you should be alright at the end of the day.
If you're feeling the pull to blow people up, just do it! Everything will work itself out eventually, I promise.
