No. There's intentionally no way of tying transactions to blocks, because block chain reorganisations or even just blocks arriving sooner than expected would cause payments to simply disappear. Solidcoin 2 has a trusted block scheme based on trusted parties inserting transactions into the block chain and it failed exactly because transactions can't be tied to blocks. Your suggested method also opens up a whole bunch of new 51% attacks.
These transactions would not be used for payments for that reason, they would just be a way for an account to sign a specific block chain by sending a small token amount (probably to another account they own). We could even force these transactions to have no output (money sent to miner) or output only to the same address to prevent using them for payment.
This is entirely unrelated to anything that solidcoin2 does, sc2 does not insert transactions into a normal block chain it just allows "trusted" nodes to create extremely low difficulty blocks after a normal block.
It would open up new attacks based on social engineering, but trust could be quickly removed by the user at any time. The decentralized nature of how each user chooses which addresses to trust would make it difficult to perform. Each user choosing small set of addresses from a few prominent forum posters and exchanges would make it extremely difficult for an outside attacker to 51% the chain. And users who choose no trusted addresses would function exactly the same as the current client. While this may not be an issue with bitcoin because 51% is not a significant threat due to the size of the network, for a smaller chain I think this type of distributed voluntary trust would reduce 51% risk greatly.