Adding spaces to text data in a cell

The only way you can add spaces automatically is to define a set of rules, then write formulae to implement those rules. If you think about the mental rules you're applying in the 3 examples you list, they are roughly
a) to put a space in if:
1. numbers change to letters
2. you recognise a distinct word (NW, Main, St, Winding, Ridge, Rd, N - and the rules for recognising the words are quite complex, e.g. not every n should be converted into N for North)
b) to capitalise
3. First letter of most words
4. Whole of compass points

Writing formulate for 3 is fairly straightforward, but 1, 2 and 4 are rather more difficult! 2, especially, requires referencing a lot of possible words!

I'm afraid that, unless you can come up with some more straightforward rules, you can't do the lot with formulae. You could get some way, by putting spaces around 'St' and 'Rd', but you'd still run into problems with words containing either or both of these letter pairs, e.g. 'stardust'.

Unless you've got thousands of rows, I'm afraid it might be easiest to do it manually...