Aviation career goals for the "older" aspirant
You have the right idea about working your way up from the bottom, but your age might limit your goals. I feel that my age limited me.
I had been flying for a few years and had earned everything but my multi ratings when I decided to change careers in 1987. I was 36. I got my multi, and with about 900 hour and about 20 of multi I started applying. There was a hiring boom at the time, so I thought I'd have a chance, even with somewhat low time. I applied to commuters and freight. I tried to talk to people, but basically got nowhere. I did not quit my day job because it was my sole income source and financed my training. Finally, ten months later, I got a job instructing at ERAU in Prescott.
At ERAU I built up my total time and multi time and earned my ATP. I continued to send out reams of resumes. In July of 1990, with about 2800 total hours and 630 of multi, and after trying for more than two years, I finally got an interview with a commuter. Two days before the interview, Hussein had invaded Kuwait. I wasn't hired. I remember clearly how there was buzz about an industry-wide hiring stoppage.
Shortly thereafter, a recession set in and George Bush went to war with Iraq. The late '80s-early '90s hiring boom indeed ended, but there still was hiring. I know, because my 25 and younger peers at ERAU were getting interviews and jobs at regionals that never at all responded to my numerous and repeated applications and resume submissions. I was 39, going on 40. Our credentials were essentially alike, but I was older. You figure out what happened.
Having said all that, I urge you to set realistic goals. There are other forms of flying where you can be successful, but I wouldn't hold out much hope about the regional airlines. There is no doubt in my mind that they practice age discrimination. There are always exceptions - I know of one or two people here who will dispute my story - but I believe that my experience is indicative of the industry's attitude as a whole toward older career-changers.
Finally, P-F-T means "pay for training." As a condition of employment you must agree to remit payment for the training you will receive, with that training being specific only to that company and with no tangible credential issuing, e.g. a certificate or rating. Start reading this thread from the beginning and/or search "P-F-T" on the board for more discussion and information than you ever will need on P-F-T.
Hope that helps. Good luck with your plans.