I know that isn't the same VisionPro stat that the pros have... not sure if it's compatible with 2 stage HPs or not, but the pro version definitely is & has more features as well. I hate to say it, but call a pro & get a Honeywell TH8320/TH8321 installed... then it'll have a 5 year warranty on it and peace of mind knowing they installed it properly.
You don't have a 2 stage heatpump....you have a single stage with emergency back-up heatstrips(AKA auxilary heat). This will be a simple wiring job for a pro......and I highly recommend the visionpro stat, set it and forget it. your wiring color codes don't make sense, so it might be working now, but later on......
If everything was always done "by the book"....the book would never change.
Put the old 'stat back in (good thing you saved the wiring diagram) THEN call in a pro to change it. Have them check out your system with the old stat in place, tell them you changed it out, but then changed it back because you had the wrong 'stat. Be honest and upfront with them. If you caused a problem with your attempted install, it will be better for them to know what you did, so they can find and fix any problems faster. It will be cheaper for you , also because they will know what they have to do and not spend a lot of time tracing down possible problems.
Nothing worse than coming into a job that somebody else has worked on, it doesn't work right when you start, you change the questionable part, and it still doesn't work. Then you have to figure out what went wrong and when, all that takes time. If you can put the original "stat back, and the system again works as it should, it will be easy for the tech to install the new, correct digital 'stat.