Seperate Partition for just OS

I’m switching over from ubuntu to openSUSE and I want to have a partition set aside just for the OS but I have a few questions

How large of a partition would I want for this?
Would I be able to have my “Home” folder on the data partition
and would this cause issues with installation of newer programs down the line?

What do you consider as “OS”? Anything that’s not /home? You’ll find that it’s already the recommended layout in OpenSUSE.

A lot depends on where you are starting from; does your current installation have /, /home and /swap partitions? If so, you should be able to install SUSE over / provided it is about 10G or more. (It doesn’t need 10G; that is just to allow for you wanting to install more programs).

If you don’t have such a setup already, you might as well backup /home and do a fresh install with SUSE.