Let's say I want to have several resellers on server. Can I set the same 2 IP addresses for every reseller's nameservers. I mean, not to have different IPs for every reseller's nameservers, but all having the same 2 IPs. If this is OK, are there any negative effects when accesing their client accounts/web sites or anything else ?

The same question would be for main shared IP which could be the main server IP

Thanks

yes it will work