Is it wrong to start the sentence with mada?
no it is not wrong
It was accepted as correct on 11/23/17. Thanks everyone who reported it!
It was marked wrong for me, but I'm pretty sure it's fine either way. Report it.
Same here.. i got wrong for starting with mada
Why is it "yamenaidekudasai", not "yamanaitekudasai"?
ないで is a fixed expression. We cannot say ないて. This is one of the things that can't be explained.
Mada kaisha wo yamenaide kudasai
The dictionary hint is wrong. It shows "任せない（まかせない）" instead of "やめない".
Leave something to somebody - 任（まか）せる
Leave/Quit a place/an action - やめる
Kaisha wo mada yamenaide kudasai
Is を necessary here? Does まだ not replace it as the partice?
Nope. In speech を can be omitted regardless whether まだ is used.
まって, を can or cannot be omitted?
Apologies, を is necessary for complete sentence. In speech it is not.
ありがとう, Maybe I'm overwhelming and confusing myself but can "から, まで, etcetera replace を,で, に?
They cannot. The possibles ones I can think of are は/も/こそ replaces が and を. The は/も/こそ adds information to the sentence along with the existing が/を.
から/まで seems to replace に as in 3時にやります→3時からやります but the から replaces the information (から: from, に: at).