Guys, you are overthinking this.
I don't see how a penetration bonus "built in by the author" could work
It works like this: the author of the tablet chooses the Penetration bonus of his spell. If you can't reach the casting total for the spell's level + Penetration bonus, using the casting rules for tablets, you can't use his tablet. Go get a weaker tablet.
That is, the author had a maximum (level + penetration) total when he is putting things together, he chooses how to balance those factors, and you don't get to change his balances. If you can't handle the total you get from them, you can't handle the tablet.
Tablet spells need a "Penetration bonus" to have a Penetration other than 0, which would not get through magic resistance.
How are the Penetration bonuses build into the spell's level?
They aren't. They are built into the casting total of the spell.
How much Penetration bonus can the author build into the spell?
As much as he can conventionally muster.
His penetration ability? With or without mastery?
Whatever he has the chops for...of course if he makes it too high, then only people with the same virtue set will be able to use his tablet.
Is the multiplier for the type of arcane connection used?
If the author says so, then yes, but this makes the AC absolutely compulsorary.
Can the author additionally specify or incorporate sympathetic
connections?
Yes, but again, these are absolutely compulsorary for every use of the tablet, if he does so.
Are the virtues and flaws of the author affecting the spell incorporated
into the tablet?
It depends. 8) Mystery initiatio,n you need. If you make a tablet with an Enigmatic Spell, the a person without Enigmatic wisdom can't cast it. If you have a spell that requires Faerie Magic, then, again, no.
That being said, if you have Magic Focus (Blowing stuff up), then no, the reader doesn't need that. If they can't get to your casting total without it, that's bad luck for them.
Does the caster add his virtues and flaws to the casting score?
He does for the writing bit: you don't for the casting bit.
If the author designs the spell for ceremonial casting, does the caster
add his Artes Liberales and Philosophiae to the casting score?
No. You add the author's.
Any single type of arcane connection to be used, are specified by the
author at writing:
Yes.
Are the example connections from AM5 page 84 enough
Yes.