Re: Cat Climbs up Door Jambs. Gouges Drywall.
Like M&T said, you've changed the rules on him all of a sudden. He doesn't understand that what was allowed before is not allowed now. Sorry for saying this out loud, but the blame falls on the people for this one, not the cat. You need to give him time to adjust.
Give him scratching/climbing options. Maybe a tall cat tree in a window that gives him a view of daily outside activity.
Wear him out with rousing good play sessions. I like toys I can control, like Cat Charmer (fleece ribbon on a wand), DaBird (wand, string and feathers), laser lights, leather strings to drag (leather doesn't get teeth/claws caught in it like fabric shoelaces do) and then soft small toys I can toss for them to catch in the air and wrestle with.
As to squirting him with water...I think that will only work when you are there. You need something that will stop him doing this behavior at all times, whether you are there or not. Here is an idea you can use to help him change his own mind about that activity:
First, you need to give him other outlets for his energy, like I gave ideas for above. Next, use double-sided sticky tape. Pet stores sell similar products for protecting furniture/walls that are very large/wide. Use these to place along the walls/doorjambs he leaps/climbs on. Most cats cannot stand the feel of sticky tape on their feet and after he tries his monkey-act a few times and gets his feet in the sticky stuff, he may decide on his own that he doesn't like that activity any more and then you can remove the tacky-looking tape.
I have a kitty I call Louie, too. Your Louie sounds much more active than my Louie!
Best of luck and keep us informed of what works to keep Louie from climbing your walls. The information you share could help other cat owners who have similar problems.
PS, edited to add:
Is that a pic of him in your avatar? If so, he is ADORABLE! He looks like my tabby/white Toby (1995-2007). Toby also liked to leap up in doorways as high as he could and then he would sliiiiide down the jamb with his claws digging grooves in the drywall. I used the sticky tape and he stopped. Then I patched and re-painted the walls and jambs.