Why "not enough RAM" is problematic is because that forces the use of virtual memory on the HDD, and the HDD is much slower than RAM, meaning that the computer is now slower. And of course "slower" is only really slower when multiple apps are open AND you are performing some RAM-intensive task, which could be about 2% of the time, or less. One or two apps doing conventional stuff doesn't even need much RAM at all.
But, wait a minute, an MBA has an SSD, not a HDD, and that means that VM will be nearly as fast as RAM, which means it will not become significantly slower just because VM is invoked.
Bottom line, "too little" RAM does not present the sluggishness penalty on a MBA that you would normally see on a conventional computer with HDD. So 2 GB will probably work fine. Your 10th tab in Safari might open 3 ms later than it would, and you can't have 50 PhotoShop layers active or mix down 150 tracks in Logic, but for the general usage you specify, no worries; you probably won't even notice the difference. A Ferrari that has a top speed of 185 won't get you to work any faster than a base-level Honda Fit, even if traffic is NOT backed up on the 202 at rush hour.
It is important not to get caught up in the trappings of conventional technology that no longer apply to newer technology, and being concerned about too little RAM on a SSD-based computer is a perfect example. Behavior based on not understanding the process and guessing that something appears to matter when it really doesn't is superstitious behavior. But understanding and reacting to that understanding is power.
One potentially nice thing about lots of RAM is that we can't predict with accuracy what the RAM needs for OS and apps will be much beyond 4 or 5 years down the road, so having "too much" right now future-proofs you if you need to hang on to that laptop for 6-7-8 years. IOW, for the vast majority of us, that probably doesn't really matter. In 4 years, I am going to be looking hard for an excuse to upgrade to a new laptop, and if my current one is still viable (and if I paid too much for too much RAM when I bought it) the argument becomes much weaker.
Lotsa RAM is always nice; if you don't have that in your MBA, no biggie. That would matter to someone with a conventional HDD, but you have an SSD instead and so the old rules no longer apply to you.
Can you say "paradigm shift"?