Spar Urethane Mess...Help!

I have a bit of a problem I need some advice on. We recently bought a new unfinished knotty alder front door and because I have a track record for making bad decisions, I let the install guy stain and finish the door. Well, I came home from work the other night, saw the door and almost cried it looked so terrible. He used satin spar urethane to seal it and it dried cloudy with brush marks and huge drips everywhere and tons of white dried in all the knots. He left the door vertical while applying and didn't even remove the hinges so it’s obvious to me he didn't really know what he was doing. I don’t want him making it worse so I’m going to try and fix it myself.

How should I proceed? I was planning on chemically stripping with a paint and poly stripper containing Methylene chloride it to get back to bare wood but I’m concerned I won’t be able to get all the Varathane out of the knots and crevasses. Do you think I need to have it professionally dipped? If not, what should I use to strip the spar urethane? The spar urethane was oil-based from Rustoleom and the stain underneath was Minwax Wood Finish.

Follow up question, once I get the door back to square one, is spar urethane the right product here? The front door is well shaded in a sort of alcove and receives no direct sunlight or weather. We live in the high desert (Utah) so very little to no humidity.

I'm attaching some pictures below:

Attachment 250996 Attachment 250997 Attachment 250998 Attachment 250999

This is with stain only, prior to spar urethane application:
Attachment 251000