I have been reading up on smart for months and have written some posts about it as well, also on my journey to get my first smartcash and be able to buy it
I am now staking in my wallet and am expecting my first rewards for this wallet
SkJbUr35DMN7iLLkRDdAHPc7HKui4qw5Sn

this one is now holding 10007 smartcash but out of those only 4000 is staking at the moment
So on the 25th I should be getting 4x 6%(ish) 240 steem
If I would leave it then I would get rewarded next month for 10000 steem and not for 10247

The sad thing is that if you remove coins that are between the multiples of 1000 you will not get any rewards.
You are allowed to add to a wallet but not withdraw as that cancels out your staking
I am here appealing to @hannahlicious and @smartcash or @hedge-x to correct me here (or any other smartcash pro) @lukestokes also wrote some good articles