Since no one is replying...
I'm curious how the WPF requirement will work and what it is... if I get 7 PT should I be fine?
13*PT WPF, after armor reduction. If you're getting 5WM you should have more than enough to get a minimum throwing level and have a few points to spare in a melee proficiency, if you like.
What WPF should I put it into, Polearm or 1H? Can the throwing axes be used to block?
It depends on what you want to do; if you want to throw all your ammo and then pick up a nice polearm to go into melee, Polearm WPF would probably be better than 1H. It also helps if you plan on using Throwing Lances in melee mode. Otherwise 1H is better; personally I just put all my WPF in Throwing since the accuracy gain is clearly noticeable, at least for me.
I assume you've already learned that axes can block in melee.
Shield skill THAT important? I would rather have 5 IF than shield skill...
The thing about a shield is that it occupies a slot for more throwing weapons. If you want to be more anti-ranged (or participate in shield walls), a shield might be a decent investment; otherwise you can spend the points elsewhere.
Also is there a mod to allow throwing weapons to be seen easier and is it worth it? Or don't bother...?
If you're having trouble seeing throwing weapons, you might want to use axes; they're much more easily seen than the thin javelin-type weaponry. Personally, I don't know of any mod that makes them more visible.
...Don't know how ammo is on larger battles..
Most of the time I run out of ammo before everyone dies in a high population server.