Re: virtual box and linux containers
I don't see why you couldn't. I personally run a Win7-raw VM permanently and regularly try any kind of distros or OSs in other VDI based VMs, all that in my Fedora 23 host (as you say, the limit is what can handle the host in terms of ressources like RAM & CPU).
The only tricky part may be in the fact that you want to test server distros, so you'll maybe have to use bridge mode for network instead of NAT, but I can't say more since I'm not very skilled in network stuff.
Just have a try : installing a VM is really a quick operation, that usually takes less than 30 mns.
no shame not knowing
only not learning