So, I read before that when you roll Skill Point Bonuses after improving in Rank that you can apply the new points to any skill that was used, successfully or otherwise, in the last adventure/Rank. You can also carry these Bonuses over, to spend them later, based on what I read in the tutorial on the main site.
My question is this: are you restricted on how many ranks you spend on a skill? If I gained Rank 2 and rolled 4 on the SPB d4, could I allocate all four of those points to a single skill, or would I need to spend each point on a different one?
1. Yes, if the skill was used successfully or not, even if untrained provided it is on the list on p35. In addition, there is a list of skills that are only available through training.
[Actual Question] 2. Your call. I would generally only allow 1 point per skill per rank except where a PC used a Skill Point Bonus [TME 1-21] allocation AND rolled the same skill on Rank Gain Bonus Matrix [1-22]. In thinking about it, I might even allow a Skill Point to be allocated from the basic Advancement Skill Bonus [TME 1-21]and a generic Bonus Skill point gained from the Rank Gain Matrix [1-22] since its coming from two sources. But no more than 2 points regardless of source into a single Skill per Rank.
There's no real indication that you have to spend the points immediately. But I would definitely look to restrict to 1-2 pts per skill per rank.
One possibility, which someone mentioned once, was that the skill points were "slots" and allowed you to train the PC if you had a skill point available. I don't necessarily hold to that as I think p35 indicates that paying and completing training grants you that "first" skill point. But that is one way to play.
Note that, in regards to (1) above, the rules on p35 indicate that you have to use that specific skill. The example given is Weapon Expert. If the PC used their Hatchet Weapon Expert but never touched their Assault Rifle, they could not put points into Weapons Expert (Rifle).
With that restriction, it makes sense that you can store skill points from previous Ranks to use later. It allows the PCs to plan ahead (make sure to use the assault rifle in the next Rank) and increase desired skills even if they get a bad roll on the Skill Point Bonus matrix.