I'm also an android developer and have experienced all these problems in the recent weeks. Here is my take on the following points:
#3 seems like its in the new market and hopefully google will fix this problem soon because it makes no sense at all. Its def a new bug in this transition to the new market that goog is probably aware of.
#4 google support has always been horrible. try calling the android market reps in support. the more devs call and express bugs they can usually foward issues to the dev team. Also stalk people on the android team on quora/twitter/google+. this works too! tried and tested ;)
#1 stats have always been bad. they go up and down and don't work for large periods at a time. our stats froze for about 2 weeks. hopefully this doesnt effect our ranking but with the secret algorithm we will never know. luckily we use google analytics and other tracking methods to account for this.
#2 market search is prob the most stressfull thing we had to deal with. for the past two weeks nobody could find out app in the market. it simply just dissapeared. we had 1000's of downloads a day that went to under 100. this def hurt our revenue and app usage decreased due to the lack of new users. prob end up costing a couple thousand in revenue. luckily it seems like they are making an effort to fix this as today we started appearing again and the search results seem to be improving by the hour.
Is the market perfect? hell no! the android market is def bipolar and has alot of problems. For us we cant live with it cant live without it. the past couple of weeks have been crazy due to the all the problems our app was having with the search bugs, etc.
Hopefully as developers we can continue to help each other find ways to overcome the bugs and help google build a quality market. Having a market that works is def a win win situation that I'm hoping to be a part of.
On the flipside these bugs have caused me to develop IOS versions of my app which I probably woudlnt have done if these bugs didnt exist. So looking foward to try that new venue ;)