In the end it seems that if you play solo (skipping heroics, flashpoints...) you fall behind at around level 40.

No, just compare the features WoW had 7 years ago without any xpac. We're not talking about content quantity here, but about quantity/quality of features.

What pre release beta period and test servers are for? To add bugs, since non MMORPG games that not have them are usually less buggy? But yes, just let the developers "Just release this buggy game, as there will always be people that will defend us on the forums with the old 'no MMORPG has ever been perfect'"

Isn't having two different people playing on the same account against the TOS?