In DD you also had to meet the requirements for learning a skill before you could put points into them. In BD the requirements have just changed from reaching a certain level to finding an appropriate book or teacher. This is much more realistic. Why would killing dozens of orcs, etc suddenly allow you to learn lockpick? It also has the potential to let the role you are playing have more of an impact on the game. Help someone out, and maybe get taught a skill as a reward; take advantage of the situation, and you could have to wait a few levels to find another teacher or book with those skills.
You don't have to worry about cross-class skills, since there are no classes, just recommended stat distributions when starting a new game. The only influence your selected skill class makes is in initial skill availability.
With a warrior/warrior skill combo you have the initial skills;
Warrior, Melee Specialization, One handed / Two handed / With Shield
Warrior, Craftmanship, Repair
For a wizard/wizard combo, it would be;
Wizard, Elemental Attack, Focused, Missile / Instant
Wizard, body magic, Defensive, Individual, Healing / Cure Poison / Remove Curse / Cure Disease
It only takes 4 or 5 fights to go up a level and get your first skill point. For a 100 hour game, this is not a huge difference from starting with 2 skills as in DD.
