There is something amiss with your calcs. An 8x50 finder has a focal length probably between 160 and 200 mm. A 15mm eyepiece would have a mag of between 10 and 15. The fov of a polosi eyepiece would then be it's apparent fov, say 50 degrees, divided by the magnification in this case about 5 to 3.5 degrees. Perhaps you meant your main scope was at magnification 60? In that case your 15mm would have about .8 degree fov.
The following assumes you meant the 15mm was in your main scope. If the Polaris is out to about a third of the finder then it is about a degree off of center. That error is about just outside the 15mm eyepiece fov in your main scope (given numbers above). Note that if you used the 25 mm you would have a larger fov than the 15mm even though the apparent fov is less. That's the eyepiece I would use to get things rolling along. In fact I would use a 32 or 40 if you have one. You can buy Meade series 4000 eyepieces for a song and they are decent for the money. All are about 50 degrees apparent fov....not high tech. Obvious you can spend a lot more and probably should as you advance. In fact for shits and grins just to get a couple of low mag eyepieces you might pick up some really really cheap Meade MA eyepieces. People please don't flame me I know they are very low end but we are talking alignment here.
If your scope is a 7-8 f# you are going to want some low power eyepieces to view stuff like the double cluster. Once you get going you.migjt get you some explorescientific 80degree boys at 30-40mm FL.
A telescope is very similar to a boat when it comes to money disappearing. Haha. If you want to keep your kids Out of trouble introduce them to astronomy...no money for anything else!
It does not surprise me the elevation scale is off. That's why it's best to use a digital level like your phone app. But it would be good to get the mount level. I have found the bubble level is about right...it's difficult to find surfaces to check level on.
The moon was full last night so stars were no doubt tough to see. Next week things will be way easier.
I finally had a chance to listen to your mount. Still not sure about it. It seems loud and i must say mine is not objectionable loud...in fact my daughter when she first heard it at the last star party remarked on how soft it was. So yours is probably not right. As others have pointed out it is not difficult to adjust. When I had to do mine I got permission from es to do it and not void the warranty. It's just faster. But it is a bit of a pain.