the tin ear flaw was so you could have a character that can't recognize music when s/he hears it.
how are jews handled in 5th ed ars magica?
When we can't figure out what you meant, it becomes a serious problem.
No such things, you'll have to come up with your own interpretation.
Ah. I was thinking a real physical tin ear... you know, an ear made of tin. 
A mere inability with music isn't a sufficient problem to deserve a flaw. Having only one ear is a flaw, as is being deaf. But bad with music? Meh.
A lot could be said about that topic. Check this article on Wikipedia.
how about jewwish magi?
If they're Hermetic magi, then in 4th edition, they'll be treated "normally". If they're hedge wizards, you'll need to check Kabbalah: Mythic Judaism.
In 5th edition, they can, again, be treated indiferently from other magi, or you can take advantage of Realms of Power: The Divine which gives you the opportunity to play Holy Magi, jewish or otherwise.
how would you fine people create shields of faith?
In your case, by following the rules on page 244 of the 4th edition rule book. 5th edition likewise has provisions for magic resistance due to True Faith.
I was thinking in terms of magic spells.
It is literally impossible. Magic can set up wards, but magic is not faith. A "shield of faith" relies on the power of God, which is beyond the reach of any mage.
Didn't you watch Knight's Tale? They all listened to Queen:!: 
shield of faith spells can be done with pius magi!
in which supplement does it say that?
(One of the DND ones? You do remember this is Ars Magica and not DND?)
well,pius magi can cast spontanious healing spells so casting sheild of faith spells sounded about right.
what do you think is a "pius magi" (or pious magus) in Ars Magica? Why do you suggest such a magus? Which book are you reading to get Pious Magi?
(Most ArM magi are quite impious... magic and the Church don't mix very well)
(And - pointless to ask, but anyway - WTF is "Shield of Faith"?)
try really, really hard to answer questions by reading the ArM books - and NO others - and to say which book you are using.
Do not rely on familiar memory and familair ideas --- all of those are clealry contaminated with DND, which we don't understand (nor want to).
No. Not in Ars Magica. Piety has nothing to do with healing. You're thinking D&D again.
see the book of god for ars amgica 4th ed(only one I know of & I don't have the book in front of me at this time)for pius magi.
Abe - you are regressing.
Pious magi is a concept from the 3rd edition supplement Pax Dei and its rules are even more remote to this forum than the 4th ed.!
But congrats on having found you way to the Ars supplement. Now move forward in Edition instead of backwards. Not only because it is what we can best relate to and help you with - but because you'll also find the 5th edition much easier and streamlined to learn, use and remember.
You could create a Mythic Companion based on being a Knight ,
and call him/her a [color=violet]Paladin.
This Mythic Companion may then take abilities from the Divine Sourcebook.
This companion may also use the Heroic Virtues from the House Mercere write-up in True Lineages.
The Shield of Faith , is the ability to generate a limited area ,
but powerful Divine Aura.
True Faith may be used to increase the Rating of this Aura.
what sort of form/bonuses would you get from the tanning/leather or whips in general?
Whips are obviously a +05 S&M bonus. 