Frankly, being able to view scores only once per week is a terrible idea. Even only being able to submit once per week isn't a very nice idea.
What really needs to happen is that viewing high scores becomes independent of submitting your own score -- and each score submitted by the same account name replaces the last. This will ensure that no one will accidentally end up on the t50 multiple times, no one will have to submit their score if they don't want to, and it will keep people from intentionally placing themselves in the t50 multiple times.
However, this is all easier said than done. It takes time and effort, and would likely involve the coding of an entirely new high-score system and table, independent of Mochi.