I guess it would work to place jack stands under the jack point pads, but to me that's looks pretty precarious. You have about a 2" diameter piece of rubber sitting on a 2 " wide flat metal jack stand pad. Since you only have one floor jack, the car is going to be pretty severely canted as you place the first jack stand. By the way it is important to have heavy duty , quality jack stands. It's also easier to get the jack pad under the jack point pad, then under the suspension subframe.

I asked about your project because your e-mail implied that this was new territory for you.
You can certainly crawl under there and drain the oil, but it is not necessary for either job.
Your engine, all MB engines, are designed for extraction of oil by suction out the dipstick tube. You can change the oil in a white shirt. All you need is a suction device. There are a few different brands out there. Do a google search on Topsider Oil Extractor, Suckup Oil Extractor, MityVac Oil Extractor. Also search this forum. Many, many posts on all of this.

Coolant can be changed without going under the car. I guess if you are going to drain the block, the you may have to go under to loosed the drain cock.

Use a good quality filter like Hengst or Mann. Use the proper coolant Mercedes Brand or Zerex G05.

Good luck.

Steve