I started a brand new campaign on e1.5.0 - e1.5.1 this month - after not playing for few months since release. I joined the Southern Empire and most of time I spend trading (until I reach skill cap), because we don't tend to be at war with other nations that often. The only way how to force Southern Kingdom to go to war (after a long and boring peaceful time) with other faction is to use Diplomacy Fixes (Updated) mod and overrule everybody in the kingdom by going to war without giving others ability to vote & decide (I don't think it is intended to work like this, as I'm not the ruler, but whatever).
I basically play as a dictator in a Kingdom that I don't rule, but hey.. I will once Rhagaea dies off, so I consider this a training of some sort! And Empress Rhagaea seems to like me so much she doesn't care that I do that (I've 100 relation with her, of course!).
btw. About the Caravans not giving XP to Trade skill. This mod should fix that for the time being:
Caravans Give Trade XP
anyways, caravans just don't survive for that long.. even if you pay higher price for more "elite" soldiers.
I wish I could form a caravan and give my companion troops of my own choice, without paying for some rather (IMO) weak troops who seem to die off quickly, but I know that would probably make my caravans OP/resistant to bandits.
btw. I made this just for fun, not to mock the game or anything, because I like it (-; but Viking Conquest remains my favourite