How do I attract investors?
Are your sure that you want investors??
I had the opportunity to buy into the company last year. I decided to leave my money in the stock market, HAH!!
But really, investors make life much more difficult. They have every right to expect a return on their investment. You are no longer working for yourself.

How do I avoid the loan trap?

don't borrow money! For years we drove 20 year old service vehicles. Only in the past two years have we been upgrading trucks. We have no investment in buildings or other overhead. Our office is a closet in the boss's basement. We have two rental storage units that hold materials. There is no shop. We do $600,000 gross sales/ year with this.

How do I get my business from "barely making it with lots of time invested" to "making a decent living, with or without lots of time invested"...?

Look at the most successful contractors in your area. That is about the best you can expect to achieve. If you live in a poor rural area, then you may be limited to being a poor rural contractor. Are you willing to move??
I live in a rural area, but it is fairly wealthy by agri standards.

I'd consider $35K net a pretty good living.
Our apprentices do that. Really man, you should consider moving and working for someone else until you get established.