I really depends on your license that you set up with Dynatrace. Synthetics has 3 levels.
The first being the lowest cost and that is a HTTP Monitor. Basically, the HHTP monitor checks a defined URL and gets an up/down result.
The second is a Browser Monitor. This does what the first method offers and provides more - also is a bit more expensive. The Browser monitor allows you to pass authentication for simulated logins, bandwidth, device and screen manipulators for you test. This also brings in transactional data from your test which allows you to see what was loaded on the page, how long each part of the load took as well as any errors. You can also set validation rules "If Welcome exists then test passes" and so on.
Lastly you have the browser monitor click path. This is the most expensive of the 3 and provides you all the same functionality, with the added benefit of laying out a user action path for the test to follow. For example, you want to test your image search platform. You provide the www.imagesearch.com/images, then you get to interact with the page as it records you steps. We type in 'Cats' then click search, then select the 3rd image. All of these steps will incur an extra cost, so use it wisely.
All of the talking point you have listed are available in synthetics. Costs will ultimately come down on what type of Synthetic you need, the frequency and amount of locations these tests need to be generated from. Which in turn is part of your license agreement. So reach out to your sales rep to get you some trail licenses for synthetics if you haven't yet.
-Chad
