Is it possible to use Scrapy to generate a sitemap of a website including the URL of each page and its level/depth (the number of links I need to follow from the home page to get there)? The format of the sitemap doesn't have to be XML, it's just about the information. Furthermore I'd like to save the complete HTML source of the crawled pages for further analysis instead of scraping only certain elements from it.
Could somebody experienced in using Scrapy tell me whether this is a possible/reasonable scenario for Scrapy and give me some hints on how to find instructions? So far I could only find far more complex scenarios but no approach for this seemingly simple problem.
Addon for experienced webcrawlers: Given it is possible, do you think Scrapy is even the right tool for this? Or would it be easier to write my own crawler with a library like requests etc.?
Yes, it's possible to do what you're trying with Scrapy's LinkExtractor library. This will help you document the URLs for all of the pages on your site. 
Once this is done, you can iterate through the URLs and the source (HTML) for each page using the urllib Python library. 
Then you can use RegEx to find whatever patterns you're looking for within the HTML for each page in order to perform your analysis.
Sitemap creation with Scrapy