That's why sometimes it's not a bad idea to hire a professional to help with certain things. I'm a finishing carpenter that installs doors and wood trims in residential new builds (mostly single houses) for a living, and after having installed probably a few hundred pocket doors, I can attest that pocket doors can get tricky at times, especially if you're not experienced dealing with them.

Good for you for sticking with it and figuring out some of the tricks on your own. Such as having to tilt the door when hanging the door onto the rollers. Also try tilting the door while adjusting the hex nuts, might give you more room. You can also remove the top trim to give you more room, if you have the tools and knowhow to reinstall it. Also, try adjusting the nuts with your wrench on the other side of the door if it's hard on one side. Some brackets are designed with a taper, and you should really be adjusting from the wider side of the taper.

And yes, tracks and rollers are not standard. That means it is important to match rollers and tracks from the same manufacturer. If you don't know the manufacturer of the track due to it being a reno, which is probably your case, making sure the rollers slide very smoothly while pulling down on it with some of your weight could help test if they fit or not.

Good luck with your project. Feel free to ask me anything relating to doors, locks, and/or trims. I've been installing them for a living for over 17 years, so I might be able to help answer any questions you may have.