Age certainly can be a barrier, but generally not so much of an issue in TP and Private Charter operations.
DCS136, I think you have a sound plan and you would be wrong not to explore all avenues which obviously includes CTC Take-Off. I considered it at the time when it first came out and then they were actually offering a discount on the initial courses believe it or not!
I tend to look at training as very much tailoring what's best for you and not what might be considered the best training at the time. Although, if you're 21 and footloose and fancy free, then that's different. But generally career changers have considerations such as partners, mortgages, children and whether that all illusive first job will pay the bills.
Flight instructing used to be a well trodden route into TP operators. It's not as reliable as it once was (what is!?), but it is still a very sound route in. We might get lucky and 'Mad Jock' might say a few words about it?
I would consider going through one of the FTO's that Flybe favour. You never know, in a couple of years time when you are doing your cpl/ir, Flybe might start taking candidates from their preferred modular providers again. And besides, they are all good FTOs, else Flybe wouldn't use them. Or Humberside for Eastern?
Another main consideration that a lot of people over look is what are you are you going to do with your new blue book? You need to have a plan. A lot of people think they will send out a load of CVs and hey presto. This rarely works and how many recruitment online applications have there been this year into airlines that have accepted fresh 200 hr CPL/IRs!?
DCS136, you've obviously considered this as you mention about wanting to instruct. A lot of people see this as a default route into the RHS or if all else fails without really wanting to become an instructor. So it is refreshing to see someone actually want to do it! But getting a FI gig isn't easy either. But leading nicely back into your choice of FTO, a FI with a 1000 hrs plus is an entirely different proposition to a new 200TT pilot. You are no longer in the bottom pile of CVs and where you trained and whether you got first time passes in everything no longer matters. Try and instruct at a regional that has TP and Private Charter operators that you can get to know. But don't under estimate how hard the cpl/ir are and the pressure that it will put you and your family under. It's no walk in the park and you need to have a very supportive missus!