Regarding Texas and the level of Blood Alcohol Concentration that is legal in public, the arbitrary .08 level is applicable only when driving.
Any other statute involving "intoxication" has three separate criteria that must be met. You must, to be "intoxicated", meet the following:
1) Outside your domicile,
2) Under the influence of an intoxicating substance (dope or booze), and
3) Presenting a danger to yourself or others, BECAUSE OF the influence of the intoxicant.
It's legal to carry a loaded pistol in your front yard in Texas, provided you have not pointed it at anyone...even if you have a beer in your hand. However, if a cop deems that you are presenting a danger to yourself or others, he must not demonstrate that you are at a specific level of B.A.C. to arrest you. He must simply demonstrate that you had consumed an intoxicant, and claim that you were under its influence...and the burden of proof falls upon the defendant to prove that he was not a danger to himself or others. This is impossible to do, which kinda legally forces people to not act like idiots with beer and guns; otherwise they risk arrest.