I usually use my longboard for commuting, not that I don't use it for other things, but it is my go-to mode of transportation.
I think it's actually more common to commute on a longboard - but I think skateboarders will tell you that it is more fun with kicktails.
If you can't ollie, you should at least learn to take curbs (going down, obviously).
A mile pushing on a longboard is no huge deal, and will be easier and easier the lower to the ground the board is (drop down, dropthrough, double drop) and harder (though not too noticeably) as it gets higher (with risers added).
Also, there are two things about board shape that majorly affect maneuverability, those being the length of the wheelbase and the height of the board. The maneuverability increases with the ride height of the board and decreases as the wheelbase gets longer. The wheelbase is the distance between the trucks on the board.
A regular skateboard will give you good mobility and pushing if you can kick-turn respectably, but just lean-turning on a skateboard deck with cruiser wheels could give you wheelbite, which could make you eat it pretty easily.
My recommendation is get a topmount longboard with double kicktails, and make sure it is less than 40 inches long for max mobility.
If you could ride comfortably and ollie curbs consistently, I would just recommend a skateboard with cruiser wheels.