Detailed Index Status Report - Is there one?

Well indeed it would be awesome if we had a more detailed view, or if drilldown interaction from the status view took you to a richer detail view about a particular category/bucket/index etc..

But in the meantime, I can answer some of these at the search language level.

1) the question about seeing stats for the hot vs warm and cold buckets.
This search will do it. (I kinda like your convention of breaking it up by command so I'll follow it)

| dbinspect timeformat="%s" 
| rename state as category 
| stats min(earliestTime) as earliestTime max(latestTime) as latestTime sum(sizeOnDiskMB) as MB by category 
| convert timeformat="%m/%d/%Y" ctime(earliestTime) as earliestTime ctime(latestTime) as latestTime

You can use a different timeformat obviously, but that'll give you a table that looks like:

category    earliestTime     latestTime     MB
hot         04/21/2010       04/24/2010     2033.864350
warm        02/18/2010       04/22/2010     8033.864350
...

2) the sum in MB per index, for each day in the last 30 days:

if you want to eventually chart it in a FlashChart, use chart:

index=_internal source=*metrics.log group=per_index_thruput 
| eval MB=kb/1024 
| timechart span=1d sum(MB) by series 
| fields - VALUE_*

If on the other hand you want to end up with a table where each row is a unique combination of a day plus an index, you'd take away the timechart and use a bin command and a stats command instead.

3) as for the actual current size on disk of each index, i dont know of a way but its very possible that someone else does.
I do know that in the output of the dbinspect command, one could tease out the 'defaultdb' part of the 'path' field, and then do a chart/stats/timechart split by that field and that could sum up the sizeOnDiskMB field quite easily...