Can I bring a sharpie in from home so a player can sign my shirt?

Yes I seen others do this

I think so, if you have level 100 seats. Your best shot might be waiting outside the stadium by the team buses.

Only if it's "Patricks"! Yes you can.

Yes

If you can get close enough, you have to get pass security, unless you have a row 1 row 2 row 3 seating

You cannot enter with cameras with a big len or woth backpacks. But I saw people with sharpies and markers inside.

Yes you can

Yes you csn bring a sharpie.