Couple of points to think about. First, your repair shop isn't shy about charging. $54 for an air filter that's 1/10 of that at the local parts place, $35 for playing with the battery, pretty profitable operation, indeed. Just MHO, but they are best avoided for future service. When it comes to flushing the trans. again, given the fact that you barely use the vehicle, unless you do something extremely out of character (towing a heavy uhaul trailer, or some other unusual event) I wouldn't give it another thought. Check the fluid level every few weeks, until you determine that it doesn't have issues, and your good for the next ten years. As for another poster claim that alignments are some frivolous waste of money, do you like having a car that goes where you point it, and doesn't destroy expensive tires? If so, alignments are a necessary part of responsible maintenance. On a monthly basis, tires need to be inspected for inflation and wear. They should show even wear across the tread, and no signs of issues, particularly on the outer edges of the tread, where scalloping, chopping, and uneven wear on the outer tread indicate issues that need to be addressed. Different vehicles have hugely different needs when it comes to controlling tread wear. I Have a CRV that will frequently damage front tires, if the alignment is off, and I fail to rotate and balance the tires every 5K miles. OTOH, I just sold a Chevy van with 125K miles and it had a gift for wearing tires down, slowly, dead even and drama free. I rotated them every year, or two, and never had it aligned.
Like most free advice on the net, you need to develop your own conclusions, based on your experience. The last two post about alignment are excellent examples. Like my van, these folks are lucky enough to own vehicles that hold their alignment setting pretty well. Taking that information, and offering the conclusion that there is no need to align a vehicle is incorrect. I have owned vehicles that couldn't wear a tire straight, no matter how diligent you were in maintaining them, and others that were quite the opposite, you need to see where you fit on that scale. Good luck.