Hi
Pilot30
Well done on securing the law job first of all.
I'm on a similar track as to what you describe - but about 2 years ahead (I have 2 years of work experience done out of 3 year training contract). I work in finance (insurance/risk management). So far I've really enjoyed it - most importantly I've made friends for life (I am going to one of their weddings' next year!), I'm studying towards a professional qualification, and am getting lots of experience in an extremely challenging role.
Graduate roles like this in finance/law teach you a lot of things which fresh-faced cadets leaving secondary school and going to a flight school won't have or experience. Learning how to work in a team, work under stressful conditions, deal with commercial pressures and how to stand up for yourself are all extremely desirable characteristics for a pilot in today's CRM-focused world.
If you couldn't tell already - my view is that it would not be a waste for you to do the training contract and save money. I'm going modular and about halfway through my PPL, timing finishing my PPL with my professional exams so that I can hour build and take a loan out to accelerate the CPL/ME/IR/APS-MCC portion all in one go.
Whilst people (rightly) say you will miss out on 2/3 years of "training captain salary" - you will have enough years under your belt of flying by the time you retire, even if you are in your late 20s by the time you're in the flight deck.
Nowadays people our age want instant gratification etc. - I've satisfied my "craving" and FOMO by doing my PPL on the side every other weekend... It's very doable.
I don't think you'd regret doing your training contract - you might regret rushing into aviation so soon though. If you know you're going to get into it eventually, doing something else for a while will only make you a more attractive candidate (IMO).
My only piece of advice is to appreciate how difficult it can be to actually save money working in an expensive city like London/Dublin when you're young and enjoying yourself. But it sounds like all in all you've given the journey a good bit of thought.
Hope this helps a little