Here's the definition of onward in the oxford english dictionary, adverb, entry 4b. In onward, the term screw up is used in place of the word “messed up”, and the phrase is not used as a substitute for strong language, or used in a sexual sense. Is negotiation room a correct expression?
Onward sounds odd and is uncommon at the start of a sentence. In british english, 'onwards' is an adverb and 'onward' is an adjective. It's the kind of thing you would write in an official letter.
Date ranges are inherently ambiguous and frequently contentious. When in doubt, be explicit. If you mean both in the sense of anticipating something, both are equally valid. However 'i look forward' is more formal;
I'd like to use it in a sentence such as there is still some room for negotiation on the terms and conditions. the idea is to show that.