I just did this - switched from a PC to MAC and I deleted all the mac os folders too because I didn't think I'd ever switch. I haven't had an issue at all, my mac read my external drives that all my kits were on. I did need to get a hard drive that I could format for the mac so I could save/write on the drive. I could use all my kits on the original drive no problem just couldn't save to it, so I opted to get a new drive to format and moved things over then reformatted the old drive. It will just give me an additional back up I figured (and I really don't trust hard drives to last forever so was okay with that).
If you just want to leave the kits on the drive (if it's an external) I don't think you will hvae any issues.