It's a glitch some people receive. Consult support@athinkingape.com if your button shows up red and you can press it to effect. Last, impossible question. Mix and match to your play style, not to 3rd party recommendation.
LastThought, 2 mil attk, 3mil def, 3mil spy attk, 4 mil spy def. how you accomplish that is up to you, I have an account like that and I love it.
Is it better to buy all the t5 buildings then upgrade them or buy one upgrade it all the way then repeat?
Go to page 49 of Wulf's guide called Buildings and Lands under the strategy section. You shouldn't have to scroll to much as it is stickies. Hope this helps