I'm stressing myself out...
Stop. It's a motorcycle. If it is causing you stress get rid of it and get a different hobby.
I don't care a whole lot about performance. I know that these bikes are capable of great performance, and it's not that I don't appreciate that, but this is a bike that will be used for the fun of cruising around, listening to the motor, and enjoying the classic look of it.
There is caring about performance and then there is common sense. in just reading this mental gymnastics to justify your decisions I can tell a few things: 1) you aren't a very experienced rider, 2) you haven't had your first close call yet.
I want you to think about this for a second - when the cb750 was new it was in traffic with drum brake cars that were better measured in yards to stop. It's greatest danger in braking was outbraking the chrysler imperial behind it. Now a 10 year old Honda odyssey can out stop you by several feet (im going to say more than 10). I'm not saying it's unsafe to ride a bike with the old tech brakes, I rode a 75K into Manhattan for almost 20 years, but it won't be all that forgiving if you don't have experience. Last weekend I had to use all the brakes on that same 75 750K to stop because of an inattentive driver - had I not had 25+ years of riding motorcycles, reading traffic, anticipating people's actions, sharpening my reaction time, etc...I probably would have been inside someone's car. Sometimes performance is going above and beyond, but sometimes it is just catching up with the traffic around you.
Anybody who just says "I am going to cruise around on it" is lying to themselves. You can't control the chaos of the environment around you. You can't keep a dog/squirrel/skunk/racoon/deer etc...from running in front of you, you can't keep someone you don't know from drinking and driving, or cellphoning and driving, or yelling at their kids and driving. You can't control your misjudgement in the face of peer pressure. If you really are a gearhead at some point some compulsion is going to take over and you are going to get on it in front of a crowd at your local cars and coffee before you realize you don't have enough room to stop before that red light.
If you want spoke wheels - own that decision. Understand the risks and weigh the consequences. Compensate for the added risk in other ways (like real gear, not a stupid 3/4 helmet and some vans) be honest with your self. don't make up excuses about "i'm just going to baby it" or "it's not here to race around on" because they are lies. I'm not saying don't do it, but if your lying to yourself, maybe that's your conscience saying you aren't ready for this yet.
Am I crazy for thinking this way?
Crazy? no, you just have your priorities mixed up. riding a motorcycle is all about managing your risk. Not just the risk the bike presents to you, but the risk you present to yourself and everyone else around you. Right now you are not doing a good job of that because it's more important to have a cool looking part than a sound functional motorcycle. It doesn't sound like you bought a motorcycle to ride it, so much as look at it, to which I say - if that is most important, make the K as pretty as possible, park it in your garage and just stare at it in a lawn chair. You'll miss out on a lot of stuff by not riding it but you'll get what you want. Or you can make your motorcycle run, stop, ride, etc...and use it like a motorcycle.
Are there any other difficulties in basically moving the drivetrain from a F bike over to a K bike and using only the K frame, wheels, and forks? I know it will not stop as well, but other than that am I missing anything big?
There are no issues other than you are hoisting a big honking engine out of both frames and it's a lot of detail work unhooking and hooking everything up proper. anything of significant difference is in the chassis. you are basically swapping a black painted engine to where a silver engine was. To do it right and dial it in properly it is more than a weekend's worth of work for a novice.
