This seems like a simple Find/Replace
Find what: ". "
Replace " "
The S1E1 is not following the same pattern, but is just a splitting. Another expression can be used for that.
regex([name], /#(S\d+)(E\d+)#/, -1)[R1] [R2]
If you want to work on an entire Name:
regex([name], /#(.*)(S\d+)(E\d+)(.*)#/, -1)[R1][R2] [R3][R4]
And to solve all at once:
replace(regex([name], /#(.*)(S\d+)(E\d+)(.*)#/, -1)[R1][R2] [R3][R4], ./ , / )