I'm hoping one day acting cool will make me feel self assured

Bro loved Dave, but his way of expressing love was so poorly matched with how Dave could comprehend receiving love that it never actually felt that way. Dave acts like Bro was some uncaring unfeeling robot who hated him, but Bro was probably the first person reading and encouraging Dave's comics, Bro was the one who bought him his turn tables and photography equipment, Bro was the one who bought or helped Dave preserve his specimens, Bro gave Dave the bed and his own bedroom even though a kid would fit better on the futon than Bro did.

Dirk is honestly probably lucky that he never got to meet alpha Dave because they would run into the same issue in the opposite direction. I think that, Hollywood obligations aside, a!Dave would be a lot more openly affectionate than any Dirk splinter. I don't think Dirk would be able to wrap his head around it, I think he would see it as disingenuous because there's no way that someone could just love him without him doing anything for it. There would have to be some ulterior motive behind hugging Dirk and saying he loves Dirk and giving Dirk nicknames and talking to Dirk all the time. Even in what was left of alpha Dave's belongings and whatever recordings he could find, Dirk probably would not get the feeling that a!Dave loved him rather than just needing him to survive for the prophecy, and what better way to encourage a kid than to get them to think that someone is in their corner? Dirk thinks he's wise for not falling for it, even though he bitterly wishes it were "real".

Drunk and Hot Girls.

Absolute worst that happens if Dirk shoots Dave in the face with a shotgun? The shot kills Dave and Dave revives with his face intact a couple minutes later. If the shot doesn't kill him though, there are a whole wealth of opportunities for Dirk. I think it would largely be a medfet thing for Dirk, but more in the way that the human centipede doctor is a surgeon than in the way that any well respected surgeon is a surgeon. It's all just exposed tissue, no one is there to make sure that dirk connects the right parts. And dirk knows (generally. It's a bit harder when you're working with a face the consistency of ground beef) what parts should be connected. It is not a matter of Dirk not knowing nor is it a matter of neglect. He knows that, if he wanted Dave to actually heal from this and look normal afterwards, he should not be doing this the way he is. Still, it's interesting for Dirk to see what Dave looks like when Dirk stitches a shred that would probably make up the center of Dave's cheek to Dave's chin instead, when Dirk leaves a prominent line of staples down Dave's split open forehead. I think that Dave would have enough trust in Dirk with the process that Dirk wouldn't even need to administer anesthesia. The adrenaline from the initial injury will act as enough of a painkiller for Dave until Dirk has gotten his fill and chooses to finish Dave off. Dave knows that he'll be taken care of after he revives, so the shock and disorientation of such a serious injury is part of the fun.

If he cuts off Dave's head, he can get some plastic wrap or fabric into the space opened up in Dave's neck. With a little time and precise sewing work, he could get Dave's head back "on" and cut the excess material from around Dave's neck to make it look a little less like he's been decapitated.

He can stir up and drain out Dave's brain through his nose, taking so much care to make sure that he doesn't damage Dave's face in the process. There were a few times when they first tried this where Dirk was too rough while trying to get the brain out, and Dirk would just remove the material from Dave's neck so that he would revive and all damages would be repaired, so that Dirk could try everything again with a clean slate.

He can open up Dave's abdominal cavity to take out all of Dave's organs. He can take his time cleaning, drying out, and wrapping the organs. He can take his time cleaning the inside of Dave's torso out and packing it with cloth and natron.

He can lay Dave to rest in more natron until his body is fully dried out, then he can unwrap the dehydrated organs (since God tier revival won't work if Dirk leaves them wrapped) and scoop out the cloth and natron that he had packed into Dave's torso. I feel like God tier revival would be capable of expelling small quantities of foreign objects, so while Dirk is very thorough in making sure that Dave's thoracic and abdominal cavities are fully emptied, he really doesn't need to worry that much. He could then push the dried organs back into Dave's dried out torso, back where they should be.

Since the mummification only really needs to last as long as Dirk wants to keep a mummified and eerily silent Dave corpse around, I don't think he would usually bother with wrapping the body back in cloth and coating it with resin and all that usually comes with the long term preservation of a mummy. I think Dirk would rather see Dave's face while he has the body, as dried out and shriveled and discolored as it is. I think there would be some times where he enjoys wrapping up Dave's body though, maybe his face as well. He'd always leave Dave's neck exposed though, so that he can easily cut the stitches and pull out the barrier that's stopping Dave from reviving.

I think that most of those times, he would just use the bandages as is. He'd get enough of a kick around Dave waking up totally wrapped, even if he's able to squirm out of it pretty quickly. Sometimes Dirk wants a little more, though. Nothing wrong with him using glue or resin to hold the ends of the bandages down enough that Dave can't get out without Dirk cutting him free (after Dirk has taken in the sight for however many minutes he wants). There might even be a couple of times where he decides to keep Dave in a little more solidly. He could painstakingly brush on as much resin or glue as needed between layers of gauze to make sure that Dave is completely immobilized by the time he wakes up.

Even though Dave is always a bit too eager to get preserved by Dirk, I think Dave would be apprehensive about the wrapping the first few times, especially since Dirk doesn't really tell him if he'll be able to move or not when he wakes up. The lack of forewarning isn't really by design, the mummification process just takes a long time, and Dirk truly isn't sure if he'll want Dave able to respond or if he'll want Dave completely immobilized and deprived of his senses when he wakes up. If Dirk was able to say with certainty what he would want in 2 months' time when Dave will be revived, Dirk would let Dave know. However Dirk would rather leave Dave in the dark than explicitly lie to him, and Dave doesn't mind the wrapping enough that he'd want Dirk to stop. When he does wake up still restrained, it's not all that bad. There's some vague appeal in still being treated like a body, unable to open his mouth to speak, unable to see anything but moving shapes in light, and only able to hear muffled sounds through layers of fabric.