Migrating Xenapp servers from Citrix Xenserver to VMWare

First of all, let me say that I'm primarily a VMWare person, and have very little experience with Citrix except for the situation I'm describing in this post.

About 2 years ago, we signed a client who is using Citrix Xenserver on three host machines.  Two are running Xenserver 6.1 and one we upgraded last year to Xenserver 7.0. As we had planned from the beginning, we want to migrate all of their VMs from these three Xenservers to two host machines running VMware.  Their VMs are all Windows 2008 R2 except for one Windows 2012 R2 that we added last year to run SQL. They currently have two servers running Citrix Xenapp 6.5, and these servers are extraordinarily underutilized.  The reality of the situation is that the Xenapp capabilities are only being used by a few firm employees to work remotely occasionally at night or on weekends.  


My migration plan's end result would be two hosts running the latest version of ESXi with a vSphere Essentials license. I have done a lot of research and found lots of posts and helpful information on the pitfalls of migrating Citrix VMs to VMware, so I think I'm OK on that portion of the migration.  However, if anyone has any very recent experience with this, i.e., migrating to ESXi 6.5 or 6.7, and has something to add specific to those versions of VMWare, I would be glad to have the extra input.

I have some questions regarding migrating the Xenapp servers:

1.  Are there any issues running Xenapp on Windows VMs hosted on VMware?
2.  Is it possible to remove the Xenapp components and reconfigure these servers as straight Windows RDS servers without having to start from scratch? And if so, can you point me to any documentation regarding the process?
3.  If we decide to keep using Citrix Xenapp after the migration, is there any trick to removing the secondary server from the farm, since it's clearly not needed? Again, any documentation would be helpful.