I think your build looks fine and good, i'd drop the 2hander wpf but you seem to be in love.
Anyway, about the quoted part: This is the reason you will need more shield skill. While normal battles don't require much shield skill (You can pick up other shields lying around, after all), it is really need in strategus. When waiting around as infantry (Which you do a lot), you'll take quite a few arrows. Also, some factions like to employ massive use of long voulges, which will be a true menace to your shield.
In short, drop 1-3 more IF and put them in shield.
This is good advice, I think I will end up dropping the IF in favor of shield skill. IF seems to be the kind of skill that you either load up on or forego, since having 2-4 extra hitpoints is nothing. Having 10+ starts to make a difference, but even then only very situationally. Also, shield skill increases your block speed and reduces attack speed penalties, correct? (I'm actually more concerned about this than how long my shield lasts, tbh)
And yes, I think build-wise dropping 2h is the "smart" choices, however, like you said, I can't bear the thought of loosing my 2h. This is probably going to be my "final" generation as I don't really have the time to grind up to 31 over and over or make alts over and over. That said I want to be able to do at least two of my favorite things: Two-handed spamming and horseback lancing.
I know roughly what wpf I need in order to be comfortable with those because I have characters that specialize in polearm and 2h already. What I have NOT yet played in cRPG is 1h + shield, which I'd like to try. I think I'll just have to "borrow" my roommate's character for a bit to get the feel of 1h + shield in cRPG and to see if it's worth splitting my points for.
If I find that 1h + shield is suitable to my playstyle and I enjoy it enough to not miss 2h then I may go this route and simply play 1h and polearm. Like many have said, there are many polearm weapons that behave similarly to most 2h weapons. (A part of me really wants to prove that a 3-way split will work, however, haha)