They need to go small scale and not focus so much on gaining market share. Scale it down to one or two devices and make it very friendly to developers. Focus on the apps everyone wants - the social media ones and get on board early to the ones the teens like, even if they fail. They are bound to be successful that way, otherwise they will continue on this mediocre path.
This is a good point. I hate having the 520/521/522 numbers for different carriers. Just call it the 520. It will delete a lot of confusion. The updates for the upcoming Lumia Black list the 520 in some cases and not the 521 or 522, leading some people to think they aren't getting the update, when they actually area. Some people don't realize that the 520, 521 and 522 are the same phone, albeit with a minor change in the 521 to make it TMo 'special'.
We should simply have a 520 (entry level), 820 (mid-level), 920/925 (for a mid-high level) and a 1020 (Flagship). Separate out the phablet/tablet 1520/2520 as a different category all together. Or, allow for free licensing and let the Windows Phone OS completely fragment all over the place like Android and gain marketshare that way.