You sound pretty motivated. This whole industry needs more people like that. Everybody's response is pretty spot on. You won't have access to empty sims and if you do that will be because you needed it for extra training. One thing you CAN use at your disposal is your peers. That sounds pretty terrible, but it's the best tool you'll have. Learn from other people's mistakes. If you truly are motivated. When you get hired, go and observe as many new hire training sims as you possibly can. Watch your peers make mistakes. Listen to the instructors give pointers and tips. Sit in on the pre-briefs and de-briefs. Always make sure that it's ok with the instructor and students because just like jumpseating, you're not guaranteed an observation. This is your access to sims. Other than that, there's a simulator for FSX you can buy from FeelThere simulations on the 145. It'll be good for familiarizing yourself with the cockpit and going through flows. It'll also be good for going through the motions of approaches and callouts.
One thing you'll need to get good at too is thinking about 3 times as fast as you do in your current plane. You'll be going roughly 180kts in simworld. You're travelling 3 miles a minute in these jets. So you've got to be thinking always 3-5 miles in front of this plane.
If you "fail" there's not necessarily a termination. Failing has multiple meanings here, so to answer your questions, it's appropriate to talk about all of them.
You can't really fail much in the way of ground school. I suppose you could, it's definitely been done, but if you're failing tests in ground school you'll probably be let go due simply to the fact that it's a very straight forward process. Failing in ground simply means you don't care and they're not going to dump big money into people who dont care.
Failing orals has happened too. That's a hit or miss thing. If you're failing your oral for showing up with no paperwork done, not following the new hire checklist, not having your ipad charged and updated, that kind of stuff may not be tolerated especially if you have a track record of these habits. If your oral is from lack of knowledge, but you really tried and you're showing it, you'll probably get another chance.
Failing a checkride in the sim rings true of every other stage. You'll usually get plenty of sims to ensure that your first shot on a checkride is the only one you'll need. Nobody is going to send you to a checkride unprepared. If you've reached your 20th sim and you just don't get it, it's probably going to be time for you and your carrier to part ways. If you get to your check and you fail from an honest mistake you're not terminated.
It really all depends on
1.) Your work ethic
2.) Your overall progress.
It's all about "reason". It's not reasonable to pay thousands of dollars an hour to help someone figure out the relationship between pitch, power, and performance. It is reasonable to pay thousands of dollars for someone who needs one or two more sims to get their non-precision, single engine, hand flown, raw data approaches ironed out and looking good.
If you are at the point where you are let go, it's like any other job. You're let go. There'll be talks before that point.
Show up with a good work ethic, make progress, ask questions, study and be prepared and you'd be very unlikely to "fail" or be terminated.