Yes. It means that the kitchen must be kept clean.
If the kitchen is dirty, the phrase would be the kitchen needs to be cleaned, i.e. it needs cleaning.
No. Since "circumspect" is an adjective, "I appreciate your circumspect" is about as grammatically correct as "I appreciate your clean". Saying "I appreciate your circumspect behavior" is correct, similar to "I appreciate your clean appearance".
compound
yes
i walked home sulkily, i had to clean the kitchen, i loathe doing that
"Why did she and I promise to clean up after the class party? muttered Kevin.
No. Since "circumspect" is an adjective, "I appreciate your circumspect" is about as grammatically correct as "I appreciate your clean". Saying "I appreciate your circumspect behavior" is correct, similar to "I appreciate your clean appearance".
My mother told us to clean the kitchen, but I forgot.
Yes. Example: "It was over almost as soon as it started." However, such a sentence requires some context from neighboring sentences to identify what "it" is.
The sentence is a complex sentence because it contains one independent clause "my mother told us to clean the kitchen" and one dependent clause "but we forgot."
I used varnish to clean the kitchen table.
My mother told us to clean the kitchen, but we forgot. A. Compound; the sentence contains a coordinating conjunction.
My mom won't let me do anything 'till my room was clean.
compound
yes
His wife was incredibly house proud and their home was immaculately clean.
i walked home sulkily, i had to clean the kitchen, i loathe doing that
She refused to eat the food because she thought the kitchen was unclean.