I'm having trouble seeing the point of this. Rent vs buy is:
a) a moot point as I already have one
b) impossible to answer as it depends on rental cost vs purchase cost vs my storage capacity vs the probability of using it again.
Let's say rental cost is 1/4 of buying cost. Odds are that if I'm serious enough about my riding to go on a dedicated bike trip, I'm probably hoping to do more than one anyhow.
So rental cost has to be a lot smaller than buying cost for it to make any sense.
The big showstopper being that I need some place to store the big box between uses.
If I haven't, my motivation to rent suddenly becomes bigger.
And to be honest, I don't have much of a problem removing either of those parts.
Anyone going on a (unsupported) trip better have more mechanic's skills than to be challenged by that anyhow, or be ready to walk/hike to the next city should anything need sesrvicing while on the road.
Leaving pedals on increase the size of the package significantly, as does wheels. Admittedly, leaving wheels on makes for a bigger but thinner overall package. Might work fine on the aircraft, but will be horrible in cars, taxis, public transportation ASO.
My current case is tailored to be as tight as possible, and require removing fork, crank, wheels and derailer. I can bring it on public transport w/o making an utter fool of myself - as long as it isn't the London Underground.
If you want to come up with something clever, try a collapsible case that wouldn't take up so much storage space when not in use. Or what about a soft case with inflatable padding? The protection of the hard case with the ease of storage of the soft case.