Please advice what is the best thing to do if you have more than 3000 XMG in your wallet in relation to staking?
Maybe better not stake at all ;-) ?
It seems to me that 3 things matter:
1) the maximum of 3000 XMG in your wallet.
2) the maximum offline stake time of four days.
3) the amount of coins in one transaction between 100 and 1000 XMG.
2 and 3 is no problem, i guess i have a problem with 1.
There is no limitation in the wallet balance. The 3000 XMG limitation is only applied to one transaction, not to the total wallet balance. So basically if you have 10,000 XMG, you'll have to split them on different transactions, for example, each transaction holding 500 XMG. Let's say 10,000 XMG is already in your wallet, set up a few accounts (add new address, and label them as like, a, b, c), and then you can move funds; open up debug windows --> Console, you can do so for a few times.
For any amounts of coins in staking, the offline time should be less than four days; after four days, the stake weight is not gaining but dropping. There is a reason that people want to keep a big amount of coins in one transaction, since by doing that they can get stake rewards as soon as possible. However, in that case, the allowed offline time is reduced, for example:
2000 --> 3 days
5000 --> 2 days
For best results, amount of coins/transaction should be between 100 - 1000 XMG; 500 XMG is recommended, whilst 100 XMG should be fine at this moment. At current network weight (about 1000,000), the expected time to earn rewards is < 1 day for 500 XMG and five days for 100 XMG. So you can see that 100 XMG is nearly the limit, since the stake weight is dropping at the 5th day.
The determination of all the parameters takes into account any future increase of the network weight; for example 500 XMG staking will receive rewards in about 3.5 days when it increases to 5000,000.