Transferable magical talents and and a man forced to shave a sea captain

This reminds me the David Farland series Runelords.

In the universe of The Runelords, there exists a unique magical system which relies on the existence of distinct bodily attributes, such as brawn, grace, and wit. These attributes can be transferred from one individual (or animal) to another in a process known as "giving an endowment". Lords who have taken many endowments become extremely powerful, almost superhuman, and are known as Runelords.

The endowments are transferred using a magical brand called a "forcible". The brand is applied to the skin, and probably requires a clear patch of skin necessitating the shaving.

I'm very late to this question, so I don't know if it's still relevant, but the description of magic sounds like The Legend of Nightfall. To quote from a review of it:

This has magic but of a type that you don't often seen in fantasy novels. Magic is an often innate ability to do one thing. Sorcerers are largely dangerous people that rip the souls from others to steal their innate gifts and use them.

I think I vaugely remember that scene about having to shave someone, but I couldn't tell you if it was this book or not. It's been years since I've read it.

I believe it is the Sheri s. Tepper books about Mavin. (The True Game Series)

This sounds like the Night Angel Trilogy where good magic if through Talents and bad magic is Vir. The Ka'Kari focused a users talent giving them a different powers depending on which Ka'Kari it was, with the Black Ka'Kari being the most powerful as it had the power of all the other Ka'Kari. There are different colours of Talent, which allow someone to use different kinds of magic.

Regarding your plot points, I can't remember specifically anything about shaving but I also can't specifically remember that not happening. It's plausible that it would fit into the plot when Blint is training Azoth.

Big finale with a fight? Well that could probably fit into 99% of fantasy books about magic..yes there was a big fight at the end, one that lasted a whole night IIRC.