Once competition has begun for the day, may the team switch drivers, or must the same two drivers remain as the only drivers for that bot throughout the entire day/competition?

Yes, you can switch the drivers from your team for each match at a competition/event, (not during an individual one-minute match).

Also a driver may only compete for one team per competition. so if you have multiple teams in your organization, one they have competed with one robot, they can’t compete with another team.

<G4> Each team shall include two Drivers. Teams with only one Student in attendance at an event are granted an allowance to use a qualified Driver from the event. No Driver may fulfill this role for more than one team at any given event.

If one of your teams only has one student show up for a competition, then you can borrow a student from another team (even outside of your organization) as long as they don’t break the one team per competition rule.

That “each student may only drive for one team” interpretation of that rule G4, does not make sense!

If a team arrives with only one student, why would another team “give” them a student for the entire event, knowing that the “given” student can then not compete at all for his own team??

The only way this rule makes sense is: “No Driver may fulfill this role for more than one team at any given event” means that a student may drive for his/her own team AND they may fulfill the role of being a loaner driver for one and only one other team.

If it is done the way a couple of posts on this forum has suggested; then the new rule G4 is just a waste of space in the rulebook: In past years, and in this year, there is no way to predefine which student is on which team; if a school has 2 teams, and 1 team has only 1 student in attendance, then a student from the other team could switch over and be part of the team in need for that event only. This has always been true, and therefore there would be no need to add the new G4 rule this year.

This question has actually already been answered by Karthik in the official forum.

No Driver may drive for more than one team at an event. If you are using a substitute, you’ll need to use a substitute that has not and will not drive for any other team at the event.

This rule has been around for a couple of years now for the VEX EDR teams. It has several intentions but primarily it is to keep organizations with multiple teams from having one or two top (Ace) drivers that jump back an forth between teams to stack the deck. (this happened fairly often in EDR)

I understand that team rosters are not part of the process, but that’s just part of the honor system at this point.

It might be easier for a student to drive for the day for another team within their organization and it may be difficult to get a team member to “switch sides” to play for another organization for the day, but if you have a team that has 5-10 members it might give someone on that team more opportunity to compete for the day. It also goes into the collaborative nature of IQ and sportsmanship.
I would very much expect that the IQ rules will continue to become more “EDR-like” over the next couple of seasons as the competition increases and teams are looking for competitive advantages.