Be afraid
Be afraid, be very afraid.
If you can stand to lose £87K then fell free to gamble it. There is many a pilot who has fronted with that sort of money thinking it will be ok and then they dont know why the company goes bust and loses it. THIS HAPPENS ALL OVER THE WORLD AND THERE IS USUALLY ONLY ONE TYPE OF PEOPLE THAT BARE THE BRUNT. YOU, THE TRAINEE PILOT!!!
" from zero hours to 1500 hours total time with JAR ATPL(f), FAA CPL/Multi IR with flight instructor, instrument flight instructor and multi engine instructor ratings. "
If you want to be a flight instructor then this might be ok but you can get all those ratings for far less and in the time it takes to get them all you will be probably have 1500 hours anyway.
My advice.... do your homework on the company and do the sums as to all the different options out there. If its the best option for you then go for it. In my opinion, you could do alot better than what they are offering.
For those of you about to slate me, this is not a slur on the company, I have no idea about the moral and financial standing of this company and for all i know they could be a prefectly reputable company with an excellent scheme to offer.
Final Words... Good Luck, you will need it!