Yes. There are currently 13 virtual nodes that handle .com and, just like for the root servers, each one of those virtual nodes is actually a group of machines

Yes. There are currently 13 virtual nodes that handle .com and, just like for the root servers, each one of those virtual nodes is actually a group of machines all bound to the same IP address via Anycast. There are hundreds of physical machines spread around the world handling the TLDs. The NS records that these servers return are readily cached with long lifetimes, though, so if you use any relatively popular DNS server, either your ISPs or Google's public server, the resolution process will be really short even for uncommon names.