Does this mean I get characters from my collection? Do I have to own the card?

Yes, you get up to 3 Sentinels that aren’t in the current game and add them to your KO area.

Can I choose Sentinels that have the same name as one of my characters?

The 3 Sentinels you bring into the game must all be different, but they can be the same as characters that were on your starting team.

In a previous round up you mentioned that if Ion Blaster of Optimus Prime was played on Optimus, then he was combined into Optimus Maximus, the Combiner could keep that weapon, however not if he was already formed. I’m assuming that also works with Laser Cutlass? Play onto an Aerialbot for example. Once combined, does it carry over?

Yes.

Since Ironhide and Optimus Prime are both components of Optimus Maximus in Wave 2, how do their unique weapons from Wave 1 interact with the Combiner? Will Optimus Maximus take damage from Static Laser of Ironhide? Can I play Ion Blaster of Optimus Prime on a combined Optimus Maximus?

Optimus Maximus would take the damage from Static Laser of Ironhide, as he is not named Ironhide. You can keep Ion Blaster of Optimus Prime if you already had one upgraded to Optimus Prime - Gleaming Commander, but you could not put one onto Optimus Maximus.

In sanctioned play, if my main deck team consists of General Optimus (Wave 3), Sentinel Ironhide (Wave 2), and Sentinel Prowl (Wave 2), and I have Sentinel Optimus (Wave 2) in my sideboard, can I exchange Optimuses (Optimi?) between games and still get the remaining Sentinels in my KO Area for an Optimus Maximus plan game 2?

Yes.