I'd agree with 52 on this. Take care with your filters and always buy sterile and USP-grade ingredients and vials and you should be fine.
With regard to EO eating away at the stopper in the vial, note that the EO is sold in a vial with a normal butyl rubber stopper. I wouldn't leave gear in the syringe with EO, though.
I have some prop 100 made with a 50-50 oil/EO mix. It draws easily though a 24g and shoots easily through a 27g and is completely painless. I haven't tried a slin pin. It was a first batch and I might go to 150 next time around.
I also have a prop/tren 100/75 blend that is just as easy to use with the same basic recipe. They'd be even thinner with all EO rather than oil/EO mix but it was my first time with EO so I didn't care to push it. Obviously, there's BA and BB in there too.