Maintinance during cycle

Hello, my two guys are having a holiday in the fridge
While they are in there I want to put some new ornaments and plastic plants in there tank, this is because I will be starting the cycle on there new tank in a week or two and want a little head start,

The tank they are in now is still not fully cycled and they will only be in there for about 5-6 weeks before the new tank is hopefully ready.

My questions are;
Will removing some existing ornament and replacing with new ones hurt the cycle?
Should I still be doing water changes to the tank while they are in the fridge?
What else should I be doing to maintain the cycle while they are in fridge?
I am also going to order my new filter online today, the new tank is 250litre I am undecided between the eheim ecco, classic or proffesional range they have three filters all roughly same price, has any one owned one of these filter ranges?

Thank you

Ok, well I have put a couple cubes of brine shrimp in tank.

Adding a bit of food is good, but I fear that "a couple of cubes" may be way too much. I would have suggested only a fraction of a cube of food. If you put in too much, you risk having the tank turn really nasty.

Replacing some ornaments will hurt the cycle, but only a little bit. The beneficial bacteria live on all the surfaces inside the tank, so you will be removing some.

Given that you are adding some food to the tank, yes, you should probably continue doing partial water changes.