I agree with most of these ideas, especially the allure of better starsigns.
The problem here that I see is candle and raven offer features that cannot be replicated in the game.
Candle grants extra talent but that's just the added bonus.
Candle healing stacks with regeneration and healing skill which makes it active always and useful always.
Raven offers the chance to get trident at a stage in the game where it actually matters a great deal.
Plus it adds 10 points of speed, an attribute that is otherwise very difficult to increase directly.
Each starsign would have to offer some desirable feature that would be impossible to replicate without it and at the same time be useful to only a few classes, to avoid ending up like the universally useful candle.
The weapon marks reductions are of lesser desirability because for characters that already use melee, there are either no penalties or there are class bonuses.
Together they make leveling up weapon marks fast and easy. That extra 10 or even 20% isn't much, especially compared to all-round passive bonus of candle.
Why would a duelist for example ever need a sword starsign? They advance in weapon marks so fast and get such amazing class power bonuses that candle is a much better choice.
It's all difficult to balance of course but certainly possible.
There could be starsigns to enhance existing class powers that are from a relatively similar area, like archers and assassins that both have class power related to missile combat.
Starsigns that would act like food preservation skill (at 80, not 100, a similarity with candle giving roughly the same regeneration as healing at 80) or those that improve the quality/amount/reduce time to create stuff - for smiths, archers or any class that wishes to use smithing.
Another starsign could provide extra bonuses to DV and dodge, maybe even double or triple modifiers in very defensive and coward modes with shield equipped.
Some playstyles would benefit from that greatly.
"Hell is empty and all the devils are here."