To answer nr 1 again, in a different way: No, 2 points less in speed should not make you do -91% hits. There must be something weird about that sword. But I'd sell it, its not worth giving it to a companion. You'd get 5k back for it perhaps..?
Well thats kind of what i'm already doing. I have around 800 renown, i just wanted to know the amount you need to become elected.
Yeah, as Archonsod points out, its more relations. And, if your kingdom already have a marshall, and the King is happy with him, he'd stay as marshall. However, if he is taken prisoner (I believe, since that happened with the last Marshall) he will loose the title, and it will be up for grabs. For that matter, my King changed Marshalls like mad for a few days.. It cant all have been due to Lords being captured..? But anyway, you are probably nearly there, just that sick waiting game.
I play on 24% difficulty, with battle size on 40 (my laptop can't handle much more) so taking castles and cities isn't a problem, i can do it on my own. Its defending them when the enemy arrive with 1000+ men thats the problem. But i don't like my castle at the moment (Dramug castle) and the king won't give me a town until all the other lords are on par with me (then my renown and relation will mean i have a good chance of getting the next) or i lose my castle to the enemy (the king likes to keep the lands balanced between all the lords i notice). But if i let my castle fall, thats my 200 men garrison gone, because my max party size is only around 100 i think. I'd prefer it if i gained a town so i could transfer my garrison over in 2-3 trips.
Plus
Well i know holding a castle is no fun, everytime i go off chasing Sea raiders to make money, the enemy besiege it, despite the large garrison (people keep saying 100+ in a garrison stops all attacks, but i have near 250, and the enemy never relent. I have 3 Vaegir lords in my tower, yet the rest see the need to free them at all costs. If i defeat their army, they just come back with more. Its not hard to beat them when i'm in the castle, but i keep thinking my garrison won't hold when the odds are 2:1 in the enemy favour, so i have to always keep coming back. This has been going on for about 2 ingame months, and i'm not getting anywhere
Get rid of the Lords. Just keep them in your party, hopefully the Vaegirs will slow down the raiding and rather ask for ransom. Ransom can be good money too! I've captured the King of Swadia THREE times! Each time they paid around 10k for him, so that's 30k right in the pocket.
However, I usually don't capture enemy Lords since it cause the enemy to hunt me a lot. I just let them go : )
And yeah, its the biggest problems with a infantry army, its slow. I play on really easy too, 26%, only adding 2% with battlesize on 100, and I have only cavalry in my party. It sucks money from you, but I speed around the map. What Factions are yours at war with? Cause all Vaegir (I guess you are at war with them), Swadia and Khergit can get you cavalry.
Sure, it will take a while to rebuild your army, but going Swadian or Khergit as a Nord Lord is no problem. I mean, your fellow Lords fight just as well next to a Khergit Tribesman as they do next to a Huskarl. So you could change your build. You can do it over time too.
Do you have any village that used to be Vaegir? That you have good relations with? Then recruit from that village, you'll get loads of troops at once and they'll might even be tier 2, or 3, or even higher (I get tier 2 from my highest village, and that's around 45 relationship).
Getting a faster army will also result in being able to swipe more Sea Raiders!
The last three portions of text in your post are sort of already discussed by the above.
But yes, starting a new game is not stupid, but you could make it with the one you have. And if you start a new one its more fun to play Vaegir then Swadian, cause Swadian is autowin at everything (maybe apart from those blasted Khergits...).