Partitioning

You also cannot enable Bitlocker with only one partition since Windows requires an unencrypted boot partition, though I believe Windows will try to create one by shrinking the existing partition.

Word Man said:

The Win10 installer will create 4 partitions for UEFI, the 4th being the MSR and never shows in Disk Management.
However, I also agree with cereberus' assertion that only 2 are required for UEFI/GPT.
As far as the MBR single partition install, the only limitation that springs immediately to my mind is you may or may not have the Windows Recovery Environment (WinRE) on that single partition, depending how you arranged it. Typically, (i.e., Win10 installer default), WinRE is in a partition separate from the Windows partition. Then again, you may not give a flip about having WinRE available, especially if you regularly and reliably take an image of your disk with a good 3rd party imaging software (Macrium Reflect being one).
ETA: I see CountMike made the same point as my last paragraph as I was finishing typing.

I was thinking along these lines also Word Man, along with others suggestions here. I'm trying really hard to understand what all the ramifications are. Don't have to do this right away so will mull it over. I'm leaning towards GPT, that way I can install More Operating Systems right along side of this one if I want with no 4 Primary limitations (Primarily one Linux OS) which will take up three itself.

I think for me, even though I Image, I don't really know enough to keep myself out of trouble yet so will go with GPT, and let Ten Format as Default with the Four Partitions it create's, that is what Ten is designed to use anyhow (from what I understand).

PolarNettles said:

You also cannot enable Bitlocker with only one partition since Windows requires an unencrypted boot partition, though I believe Windows will try to create one by shrinking the existing partition.

Thanks PolarNettles, this is also something I need to explore...so little time.

Actually, it is not a requirement of UEFI to have two partitions - just that the boot partition is fat32.

This is how Rescue drive from tools like Macrium Reflect Free are setup ie all files on a single boot partition.

Of course, full Windows has to be installed on NTFS (would it even work if on fat32 aside from fat32 limitations?), and hence this leads to the practical limit of a minimum of two partitions for Windows in UEFI.

Having said that, some bioses can boot from NTFS even on a UEFI install, and I believe it is possible to boot with a single partition BUT this is not adhering to the UEFI standard.