Thats correct.
No idea what dirty means, but will be removed in future versions.

It pulls in the dirty suffix from the code source while compiling, but can be fixed for the upcoming releases.
See here in Bitcon for an example: https://github.com/bitcoin/bitcoin/blob/master/share/genbuild.sh#L38

well, the calculator suggest your average reward should be about 1.2 MUE per day.
As rewards are paid in a block of 18 MUE, its likely you will have to wait around 18 days to be lucky enough to win a block.
It's possible you will never win a block though of course as staking is just like mining and you are competing against much higher staking opponents.

Can I stake with android wallet too?

I guess so if you haven't upgraded to 2.0?
Make sure you read the readme file;
https://github.com/muecoin/MUE

add these nodes dns1.monetaryunit.org dns2.monetaryunit.org dns3.monetaryunit.org 192.99.217.102  164.132.151.109

18:19:52

Welcome to the MonetaryUnit RPC console.
Use up and down arrows to navigate history, and Ctrl-L to clear screen.
Type help for an overview of available commands.


19:30:05

importprivkey KenterYourPrivateKeyHere "comment"

Join us in discord
http://discord.gg/5PD3X7G

https://muetv.com/

https://www.monetaryunit.org/calculator/

You decide

HI
MUE is POS  Masternodes  only now


thanks
Paul