BoFlyer,
As as someone who had a similar background to you coming in the industry (a bit younger when I did it), are you sure you want to go down the airline pilot path? Why not just continue working in the family business and growing there until you either can take on a larger and more profitable role? While you do this and even if you end up selling it, you can enjoy the flying and being a CFI. Or you can use your CFI and network into a SIC role for a Part 91 operation and fly for fun when they need you on a trip. There are many paths in aviation, and being an airline pilot is not necessary to feel like you've "made it" when it comes to flying.
The road to being an airline pilot is long and grueling and I can assure you that you won't be "killing it" for many years, if ever. What am I trying to say is that thing long and hard before giving up what you currently have while just flying for fun. I did make it to a legacy and a youngish age, but I have those moments often thinking "what if".
Best of luck in whatever you decide