Maybe I'm misunderstanding, but phonetic matching is already included in search results. We're not introducing any new variations to search results. (You are correct that phonetic, like Soundex, is better for Western European names than other types).
As for the things you would rather see. We are taking a methodical approach and will do further tests as we go along.
I do want to clarify one thing you mention. If you enter a death date of 1869, you should never see a census for 1880+. Our lifespan filtering will filter that out (you may see 1870, however). I think the issue you are talking about is when a record doesn't have an explicit life event date associated with it. Our lifespan filtering uses life events (birth, marriage, residence, etc.) to determine whether a record could have been associated with a person. If a record doesn't have an event date, It doesn't get excluded. The problem is that some of these records have an implied date that clearly (to the user) makes the result irrelevant. The problem you mention is valid, and is somethign we'd like to address, it just won't occur (unless a bug) with the specific databases you mentioned.