Greetings Michael
The quality control issues with PAL injectors I am sure you will find was only with some of the PAL Adjustables where the head (frame) in some was machined on the 'skew' I doubt you will find any issues with the Injectomatics.
Those PAL blades by the way will almost certainly be carbon steel with a layer of machine oil on each blade, no doubt you will want to try one, I have and they pull like a train to the point just short of when your eyes fill with tears! Incredibly inspite of this they shave really close but the pulling is just not worth enduring for the end result.
I have never worked out if these blades were crap initially or whether they have simply degraded with the passing of the years; perhaps it is a bit of both.
With regard to using the Feather injector style blades I have not tried it, obviously you will need to snap off the excess, I did a couple of years ago read an article on one of the forums about it but I am unable to now find it, I suspect you would not be able to use the Pro guards because of the little whiskers binding as you inject the blade.
I personally like the Schick G's they shave very nicely and are not as fierce as the earlier E models, I get on well with the Personna PTFE blades that Paul from Connaughts sell.
Regards
Dick.