You should be able to open the .amxd M4L devices in max - you can try this even without buying a Max License! Some of the M4L devices though are expecting to receive data from Ableton to work though - MIDI notes, clock etc. Simple modifications would allow them to work with other data sources though.
I am working on some devices that will be for use natively in max so that you do not need an Ableton license or a max license - all you will need is Max installed! You will be able to run the patches in max runtime mode (unauthorized) but not save your own changes. If your desire is just to use pre-made patches built by others, then you will not need a license, but you will need to wait until they are published by whoever is making them!
If your goal though is to program your own max patches, then the answer is yes, crow is totally hooked up to Max! Go for it! All the M4L devices are just plain ole patches with special communication channels with Ableton.
You can always download the trial and see how you like designing in max!