***Any general tips about owning this car would be greatly appreciated!

Yesterday I got a 2013 Hyundai Elantra GLS Manual with less than 30k miles for $6k, rebuilt title, repaired, beautiful deep blue, nicest car I've ever owned by far, so far I love the little thing. (that trunk/back seat space though!! How?? Where did it all come from??)

Last car two cars I owned were from 1988 and 1995, I am just wondering what fluids and other markers of wear I should watch for to make sure I can drive this car to 200k miles, hopefully without replacing the engine! I just have a question or two hopefully for someone who's owned this car a while, or a similar one with related parts.

I am also trying only to ask questions I couldn't find answers for on this website or others very clearly, no one likes redundancy.

1.) It's like 4 degrees Fahrenheit where I live right now, I know tire pressure gauges are notorious for always being on no matter what you do, do I really need to check my tires if that gauge is always on?

1.5.) Anyone tried throwing a bag of salt or two in the trunk to help that thing stay straight? Not trying to wear it out, I know the OEM shocks are not that great, just wondering if it would help on ice.

2.) Best car seat covers you found? Not looking to spend over $125, there are so many options, I don't know where to start! (would like both front and back seat 40/60 with armrest)

3.) Best type and viscosity of oil you've found? I understand "best" may not be a really appropriate word, I more am looking for oil that is going to work with this type of engine well, and not wear any seals. I am willing to pay for expensive oil, I've always just run Royal Purple full synthetic so far.

4.) Best fuel injector cleaner? I've always used Sea Foam, works wonders with carburetors, not sure what it does to injected engines.

5.) Weird I can't find the answer to this question but, will the passenger airbag "OFF" sign disappear when someone sits in the passenger seat? I have heard some cars have that design.

Thanks everyone for your help, any other tips about good replacements for all the OEM parts in a few thousand miles or so would be appreciated and considered too, I look forward to participating in the forum here!! Thanks!