My ds goes to Chiswick and I have been pretty vocal on other threads about the school.
I do not recognise the school from your description and I don't think many Chiswick parents will recognise it either. It is not a badly managed school, there is now a new Head in place for September, the Governors have restructured (were actually in the process of doing that when ofsted came) and they are expecting an ofsted inspection imminently (this term or next). The measures that they have taken in the light of the RI rating mean they do expect it to go back to Good and the interim ofsted inspections that are required as part of RI have indicated that the issues within the last report have been addressed.
Pastoral care is good. Quality of education is good. Teaching is often inspirational. It has one of the best History departments in England (by results).
It is a local school - the catchment has been shrinking regularly. It was at 4 miles at one point. By the year my ds started it was down to 2 miles, he is in Y10 and it has gone down since then too. All my ds's friends are within walking/bike riding distance. He is in a group of very bright, very hard working high achievers and absolutely loves the place and is intending to stay for 6th Form.
Of course you can move to Chiswick and not go to the school - there are lots of good local schools from the WLF to Isleworth & Syon to the Green School for Girls and from this September, the Green School for Boys. So if you like Chiswick then come and live in Chiswick.
Do PM me if you want to ask anything at all but also do go round the school - the open evening is usually the first Thursday in October so put it in your diary, come and have a look. The new building will be open by then, the new Head will be in place. I think it is interesting times for Chiswick but not in a doom-mongering way.