I would probably finish up to the garage door, leaving the outside threshold concrete.
If i sloped the transition, how could i address the slope and the "level" garage slab? Would grout be alright? or are there any particular transition pieces that would work for this?
For a porcelain tile install, how would you address this transition within the garage? Level the concrete? Tile around the transition and install Schulter Reno?
If you're not framing the walls/ adding sheet rock, I'd recommending installing cable in EMT conduit.
If the walls are framed... i'd just run the cable in the wall
I think I may be hard manufacturing the sleeve itself, if it's made out of titanium plate. That would work if it was forged or cast steel.
Also, that would require splitting the open and box ends into two separate pieces.
If all else fails, you could probably use bolts/nuts for fastening the wrench to the handle, but it would to a degree defeat being able to quickly change your wrench.
You would have to work out the design of the pins and the method that they would be installed. They would have to be engineered to withstand the shear during use. I'm not sure how easy it is to weld to titanium, but it seems that it is a very tricky material to machine.
On the other hand...