Can the token for all meters be generated at once (to a platform like excel) to be distributed to all customers?

Yes, but this is very impractical since the spreadsheet can be very large and confusing for customers to use.

Can the 2 tokens be issued out to the consumer to insert instead of sending out technicians to all houses?

Yes, this is one of the options available to you.

Does the STS have a TID Rollover Project plan template?

Yes, they do. Please refer to the TID Process Tab

Also, a bit technical: Please explain, since a KCT changes SGC, TI, KRN, how it relates to the change of the base date?

A new vending key is generated for the new base date, still using the original SGC. Note that a KCT may or may not change the SGC – for example, you may go from SGC123456 to SGC123456, but only change the TI.

Is the purpose to increase the KRN or otherwise?

The KRN will change when doing the TID rollover in order to ensure that the meters keys change. A new vending key will also be generated to ensure that the meter keys are different.