I tend to allow banking of skillpoints & feats as an option to allow the game/story flow. For example if one were to keep a few skill points open, then if the opportunity arises during the game such as an NPC willing to teach a certain skill or give knowledge that the PC would like to learn than if the PC has time (it may vary depending on the how complicated/rare the skill may be) than the PC can learn it.
The Group was aware that they may end up having to travel to another plane to complete their quest. Ranin the Rogue had expressed a curiosity to learn more about these mysterious universes. Jarl the Wiz had some knowledge(Planes) that he learned while still in school. So while they were on the road to their destination, Jarl would tell Ranin of what he learned everynight as they settled down at camp.
With the flow, it's lets the PC get the feeling that he's able to learn things as he goes along the story, not just in stops and starts depending on when you gain your level. So when it comes to skills or feats that may require training, I find it doesn't make much sense that while exploring a crypt and gaining a level, the party wizard suddenly becomes aware on how to construct a magical staff. But perhaps after fighting their way back out, and having some R&R that wiz could learn that feat. It depends on the player really, some people do want to fill out their feats right away, some want to keep their Minds open to learn as they advance. (such as the fighter having a new feat, but the one he wants has a prereq for the next level)
