I got that part. What I meant was asking if you are going to spend those coins often. Once you move your wallet from the offline machine to your main one, your wallet will be completely exposed. You can mitigate that by preparing transactions on the online machine, signing them on the offline one and moving the signed transaction to any online PC. This won't expose your private keys. Also, I don't think that using virtual machines is a good idea. If your host is compromised, so are your VMs. Using a separate computer would be safer but I might be overreacting.