Well i can respect you wanting to see your team on the road and get a different experience, so congrats on picking this game...
just a word of caution this is only my .02 cents so take it for what its worth... If you plan to wear your texans gear dont act like a tool just be a happy easy going guy and joke around and have a beer, no one should give you a hard time if you do that and some people might want to chat about the texans and will probably treat you pretty well if you come off like a decent guy... but if you start getting cocky you might have a problem with about 5000 really drunk guys... not kidding...
play it cool and you will have a great time.
In all honesty we dont have a very big rivalry with texan fans so i cant see people giving you a hard time the second they see you... but if you were a pats/raiders/jets fans you would be instantly heckled without mercy
"game day" at the ralph is more like college than the NFL.
there aren't any hotspots per say right by the stadium its out in the burbs and its basically a giant parking lot which becomes the party. there are a few small bars at the corner but nothing what i would consider a hotspot.
things to do-
niagara falls is 30-40 mins from orchard park (where stadium is) if you go, honestly dont even waste your time on US side go right to canadian side. (for what its worth canada is about as close to the US as a foreign country can be, other than different road signs and a minor accent you wont know your in another country) the "clifton hill" area is a huge tourist trap but there is a lot to do some bars/clubs/casino/tourist things, but if you are looking for more "adult" entertainment check out lundys lane and either go to seductions or sundowner, and bring lots of american singles (they have more use than canadian loonies and toonies for a specific purpose of how you can place a folded dollar bill) you will thank me...
if you dont have a passport for canada (you never used to have one, its a new requirement) you cant go wrong checking out "chippewa" in downtown buffalo. its mostly college and 20-30 yr old party area. a bunch of bars and clubs. oh and we like to drink here so bars serve till 4am!
other things-
The the best wings, check out Duffs or Buffalo Sports Garden both in orchard park and less than 5 mins for the stadium. They are fun local sports bars if you want to hang out and get a feel for things and get AWESOME wings. they are not "buffalo wings" they are chicken wings. (anchor bar is overrated)
other "unique buffalo chains"
check out ANY local pizza place for awesome pizza. teds or louies for hotdogs, mighty taco for hangover food, or get some beef on weck at Dannys (close to stadium)
grab a case of labatt blue light and enjoy
buffalo isnt a big metropolitan area, its very easy to get around without much traffic. only time you will have a problem is in "bills traffic" it gets backed up but if your form houston it probably wont bother you.
dont be too hungover sunday morning and be waiting in line at the stadium for then the gate opens at 8.
last bit of advice..... DRESS FOR THE WEATHER.
have fun