Firstly any kind of stat boasters could not removed. So they are out already. They are also a main part of your idea since these will have boasted a player quite considerably.
creatures wouldnt have to be removed, where all these problems could occur but it might be easier if they are just disabled for a period of time. Again this will require a lot of coding for Mur
Tokens again would have to be disabled, Not exatly a great deal but again it would require more coding for Mur
The shop could also be disabled for the day, again which will need to be coded.
and yes becuase the stats would still be there it would be just like rewinding back a year and a half when there were only about 3 rituals that anyone used so they could win and that your stats nearly always mean if you would win or lose.