Sure, I suppose reducing the memory to level ratio would hurt most at the beginning, but I think it's a pretty minor loss when you can just throw in an extra point or two in memory to make up for it. On the contrary, I'm a bit worried the memory inflation will become more of an issue later in the game, where investing in memory will feel like a waste, especially for non-hybrids invested in one skill tree (like rogues).
Skills with higher memory cost (besides source skills), could help with the issue too.
Skill requirements can easy be changed. 1 ability point minimum to learn a skill should probably stay though, you're right. Right now the skill "ranking" does seem a bit arbitrary. The way I see it, rank 1 skills should be primarily basic or fundamental skills for a class, mostly requiring an appropriate weapon or stat investment. Level 1 scoundrel skills might be Vault, Throwing Dagger, Sawtooth Blade, Chloroform, and two or three more minor buff or debuff skills that don't require daggers (so a non-dagger rogue hybrid has a couple options for rogue skills at the start.) The more powerful scoundrel utility skills like adrenaline and cloak and dagger would require 3 in scoundrel for best use.
I think a major issue with memory is the attribute burden it imposes on hybrids. The way I see it, memory's main purpose is to limit the versatility of mages from going to the absurd like it could in D:OS1. But hybrids already deal with a split attribute penalty (unless they use only utility skills from their non-dominant tree), and so a third attribute to deal with the extra skills to memorize might be a bit too much to make hybrids viable.
An interesting talent could help: When distributing 4 attribute points equally among two different primary attributes (strength, int, dex), you gain 1 memory. So someone with 12 int and 12 strength would gain 1 extra memory, and 20 int and 20 strength would gain 5 extra memory slots. If too strong, then 6 attribute points split equally for 1 memory might be balanced (e.g., 13 str and 13 int for 1 extra memory).
