My opinion:

1) Level 1 if they don't care. Up to level 4 if they really care. Of course, if you look 30 they probably are going to wave you in if they are just worried about alcohol laws.

2) Level 2 to 6 depending on how well connected the cops are. Getting stopped in the UCAS by the "FBI" with a UCAS SIN will tend to be a lot tougher than a rural cop in Athabasca against a fake UCAS SIN.

3) Level 6, but customs and border guys often don't even look and just wave you past if you look ok to them. I'd give them a 5 perception skill (they do this for a living). If they don't think you are a terrorist, lying or hiding something, they typically wave you past. If they check and your SIN shows good but they still think you look like a skank they get to strip search you, take your car and luggage apart, etc. So they get to try again, assuming they don't find the hand grenades in the fuel tank. That gets you a trip to jail and they get to try again with a higher rating.

4) Level 4 - 10. Don't get caught by SK in Frankfurt on an SK SIN and locked up, etc. National governments, well connected local megacorps are really bad, big cities are not good, small rural lockups are not too bad.

Don't get caught, and don't turn a ticket for a bad tailight into a trip to jail.

I'd argue that if it passes two checks at a level 6 - 8 you they are probably not going to blow the ID ever. Unless they are really interested in you. If you have created so much heat that they start heavily checking your backstory, like calling your cousins, visiting the place you claimed to live two years ago and talking to the landlord and neighbors, and finding your high-school teachers and showing them your picture things are going to go badly.

So if you are by some miracle taken alive after shooting 8 cops you are toast. They get you for knocking off the Stop'N'Rob without anyone getting killed it's probably not so bad.

TR referse to "table rating" which goes up as the players karma goes up. The above test is pretty trivial.

Personally I vary the rating not just based on who is doing it, but how much they really care, based on the idea that the better verification schemes take more time and have to bother with collecting things like biometric data. There may also be some cost associated with doing a thorough check, much as there is today, though not as much. So if you stay polite and don't raise any eyebrows I keep the ratings lower (this also helps keep charisma and ettiquite from being ignored by the non faces).

Typically you'll want to save rating 5 and 6 scanners for cases where the characters are in some trouble, or the situation is one where they really want to know and would pay for it, as those ratings have a rather reasonable chance of blowing the chars cover.

Most places like a bar and such just want to get their money without much cost. So having lots of rating ones (unless they do something to make someone suspicious) is appropriate. Remember that a rating 3 or 4 stick is still supposed to be useful and they'll get one or no hits all to often.

What place just waves you through? Where have you been traveling? Any plane trip I've been on recently has had multiple security checkpoints. Th airports in america you go through metal detectors and go through checkpoints where you have to show your passport. With the simplicity of checking ID's in SR I'd guess that everyones sin goes through a checker. Mexico has random searches. You press a button if you get a green light you go through and if you get the red light they physically search through your stuff.

I'd say going through customs in an airport would really tough. You would have to go through a MAD scanner, probably a high rating one, there would probably be a cyberware scanner also, your SIN would go through a high level ID check, and you would be subject to random searches.

Border crossings are completely different. They would probably get to roll judge intentions, If they beat you in the opposed test they would physically search your vehicle. Your SINs would also be scanned in the identity check. The rating would depend on the country and how often the road is traveled.

Since they did in 1st, 2nd, and 3rd Ed., I would say yes, they still do.
If memory serves, any hardpoint (drone or vehicle) provided 2 points of recoil comp. The LMG in the Jeep example uses a pintle mount, but I don't recall if that provided different recoil comp than a regular hardpoint. The idea of using the bipod rules sounds good to me until something more formal come around.

The drawback of the typical Fake ID (outside of ones created by intelligence agencies, etc) is that there is no there there. So they can always be broken with some legwork, no matter how good the electronic background is.

When they call your mother, who answers the phone? What does your supervisor say when they call him at work? Does the company pay record match your bank records? If they show your boss three photos, can he pick you out? Does you DNA show you are related to the rest of your family? Will they recognize a picture of you? Does your travel, commlink call logs and spending trail match up with your ID? Does it look like you really live at your residence? Whose DNA/fingerprints are there? Does your commlink call records match up with your timecard/call logs at work? Does your car autonav records match the gridlink records and fit with everything else? Does the odometer, service history and tire condition match the your ID?