Houseruling Call of Cthulhu - yet again! Incorporating Trail features

I have thought about suitable ways of incorporating the nice features from Trail of Cthulhu and think I have finally nailed it down.

• Pillars of Sanity - So, pillars are abstract principles your character believes in. Everyone get for each 20 pts of SAN. 

1. Advantage: When faced with a horror that invalidates your belief, you can have the Pillar crumble and avoid the SAN loss. When all your Pillars are gone, you will automatically fail your SAN rolls when nothing shields you from the horror.
2. Disadvantage: When faced with a horror that threatens your Pillar you will always roll the worst effect when failing a SAN roll.

• Drives - Drives are core desires of your character, which gives you a reason to go mad and die.

1. Hard driver: Following a hard driver will protect you from the effect of losing 5 SAN in one go for the next immediate experience related to the driver. Ignoring the driver, loose 1d6 SAN.
2. Soft driver: Following a soft driver and you will only loose the minimum amount at the next immediate experience related to the driver. Ignoring the driver, loose 1d3 SAN.

• Core Clues - While I don't expect to use it as a hard and fast rule, professional skills will always give the clues needed. Characters should shine when doing their thing. I'll always ask for a roll, but if it is a core clue check, failure will not stop the clue from being found but instead will take a significant amount of extra time, say all day instead of an hour.

Then there are one thing I am looking at importing from Unknown Armies, and a small tweak to the basic system.

• Trigger Events - In Unknown Armies your character have an event in their history when they encountered the supernatural. I think that is a good idea for thinking more about who your character is. It's probably also a nice way to tie into the Drive of a character.
• Skill improvement - In older editions of CoC you didn't gain 1d10 when rolling for improving a skill, but 1d6. I love my d6. I do like the idea of extra effect for crits, though, so crits will gain you 1d6+1.
• Regaining SAN - Sandy Petersen's original game didn't have the option of regaining SAN. I like the starkness of that rule. Taking a cue from ToC, I'd rule that if at the end of an adventure there are no physical evidence left for any unnatural event, you can regain SAN. Roll a d6 and be happy.