Few questions about a few sentences I came across in Rosetta Stone.

Извините, что значит это слово - For this sentence just wondering in what case all the words are in. For example if it was a feminine word in place of слово would Эта decline to Эту. Also where does что come in this. In the form Subject - Verb - Object how would this sentence look, just for my peace of mind.

Does Это have a separate usage apart from that where Этот is the infinitive (masculine nominative). For example Что это, is used when you can't possibly know the gender of what it is your observing.

Any other uses for Это?

And finally, observe this picture from Rosetta Stone, I'm fine with most of it until it says Такое instead of Такой which I would expect as Стадион is a masculine word.



EDIT: also noticed Это стадион instead of Этот in the last panel... I'm sure there is a logical explanation

What gives? Thanks.