I have played thru a couple times now, but i have largely ignored certain skills that i would like to get the mastery bonus on and now I am wandering what the bare minimum CP investment is to get mastery on them. assuming a male human with no background and no final god blessing: gambleing, haggle, spot trap, disable trap, and persuasion what are the minimum CP investments and the items or blessings needed?
The trouble is Disarm Trap is a tech skill, and the Ring of Influence which allows for skill bonuses to Haggle and Persuasion is magickal. In light of this, the best you can go for is Halcyon's blessing and then Kerlin's (what I would do is complete the first two circles and then get all the other blessings apart from Kaitan's to accomplish this as you get a lot of other bonuses). If you're into a bit of light theft, the Lucky Medallion on the guy who patrols around Poone's Flophouse in Tarant will save you a point in Gambling (you only need 18, or four and a half CPs, to master it). This means you'd have to invest 5 in Disarm Trap, then 4 in Haggle, Gambling, Spot Trap and Persuasion - making it quite a character point expensive build. If you were planning on using Therapeutics, then the Potion of Persuasion can save you another point in Persuasion - but as the first level costs a character point in the first place then you should only go for it if you're actually going to make use of the higher levels of Therapeutics.
I don't always, it depends. Sometimes I like to role-play a character who's self sufficient so they wouldn't like depending on a substance for power necessarily. Other times I can't be bothered with the carry weight or continual usage of them in dungeons or when a skill you need to use in town relies on an attribute you need to boost. In any case, you can consider a point in persuasion "saved" if you are leveling up therapeutics already and are happy using potions of persuasion when the need arises.
...a point of persuasion and at least 5 stat points(dex, int, str/per{melee/guns}). For saving points its even better that electrical.