My 7th level human fighter (RMSS) had Anticipations and Cloaking spell lists (both Mentalism Open) to 2nd rank. With Anticipate Missile (1st level, instantaneous spell) he got a +50 DB vs ranged attacks (not spells, that come from the 4th level spell on the same list, Anticipations) for using a 10% action, translating to a -10 to other actions, like say attacking. The second level spell allows him to do the same for melee attacks. With the Cloaking list, the first level spell is Blur (instantaneous) that causes all attacks to have a -10 for 1 minute/level. The 2nd level spell is Shadow which grants a +25 to +75 bonus to Hiding. How many skill & category ranks would it take to get those bonuses? I think the DP cost is well worth it. Using those 2 spell lists alone, I made my fantasy Batman, a fighter who could sneak real well and was pretty dang hard to hit. (We also used Talents & Flaws from Character Law, so he had some of those that helped out too.)
Any fighter who would like to have a better chance with resisting magic should get some ranks in Spell Wall (Open Essence); I would say up to at least level 5 for a +10 bonus for 1 minute/level.
As for the farmer, just getting 2 ranks in Weather Ways (Open Channeling) would help out immensely as being able to accurately determine if it is going to rain* in the next day is worth spending the DPs (once) and 2 PP/day (during the times of season they need to know). Plus, getting Purifications to 4th level means they can keep their livestock healthier than otherwise, so less loss to disease, and less chance of spreading it to other animals. As farming is a family affair, I would assume they would develop traditions in who the different spells/lists would be "handed" down to - which could be some pretty-cool world and/or character background flavor.
I will say this: my greatest experience in RM is with RMSS/FRP, I only played a little RM2 back in the day. I do believe that in RM 2 it is more of a risk to try and learn spells because there is the chance that you don't get the rank on the first try. (Right, that is a thing with RM2?) Of course, even then we never did that; if you earned the XP to go up in level and you spent the DP on the skill, you got it, even with spells. In RMSS it is not a thing (unless it is one of those rules that is hidden deep within the bowels of the rulebook that I have never found - entirely possible). Heck, in RMSS/FRP an Urban man starts with 2 ranks in a spell list (Open, Own Realm). Bamn! Right off the bat at 1st level, any pure-arms user could have access to 2 spells if they only spend DP to get 1 rank in Power Point Development. High elves get 4 ranks!
*Modern construction crews would love this spell, it could tell them if they should concentrate on indoor projects or outdoor ones before the day before. I think my brother-in-law would love to have that spell.
