you can point a domain name at any number of servers. your visitor's sofware will pick one of them at random. unless the servers have identical content it may be confusing for the.
for a real life example (of this confusion) try
try it again tomorrow and you'll probably get a different website.
I don't know that there's a limit.
you may have to transfer the DNS hosting to another provider, but there's no problem having two servers on different IP addresses serving one domain name
eg: google does it.
the three type 'A' records are three servers probably in different locations.