As a rule of thumb, if you plan on retiring at level 31, plan for a level 30 build (which you've done). But to do that, you would generally want to get a number divisible by 3 for your attributes, so as you can see, those 2 leftover attributes won't help much. I'd recommend for almost every level 30 build (if you plan on retiring at 31) to convert 2 skills to attributes.
That way you could go 18/18, or 15/21.
I would either choose throwing and 1h/shield. Or throwing and 2h. Your best bet is going to be 2h (IMO).
The weight of your gear lowers your effective WPF, and for every point in power throw you automatically lose 14 (or 13) WPP in throwing proficiency. If your ACTIVE throwing WPF is 0 you won't be able to pickup throwing weapons after you throw them.
I don't have a throwing hybrid, some of the Norse Horde guys would probably be able to give you a good build, but tinkering with the character calculators (
http://alpha-lider19.ru/MB/ - I only use for determining the actual WPF I will be able to have in different weapon types. Or
http://infinitum.dyndns.org/crpg/calc.htm - for planning my build)
If you go throwing + 1h/shield I'd recommend something like 18/18 build (something that adds up to 36, you will need to convert 2 skills to attributes). Or if you go throwing + 2h, then I would do something that adds up to 39 total attribute points (18/21 maybe, and have to convert 8 skills to attributes).
Strength: 18
Agility: 18
Hit points: 59
Skills to attributes: 2
Ironflesh: 3
Power Strike: 6
Shield: 4
Athletics: 6
Riding: 0
Horse Archery: 0
Power Draw: 0
Power Throw: 4
Weapon Master: 6
118 1h
119 throwing
^these can be changed around to suit your wants/needs
Strength: 18
Agility: 21
Hit points: 53
Skills to attributes: 8
Ironflesh: 0
Power Strike: 6
Shield: 0
Athletics: 7
Riding: 0
Horse Archery: 0
Power Draw: 0
Power Throw: 4
Weapon Master: 6
Same WPF as before, but swap 1h with 2h