I suggest that you do not buy any XMR (or any other currency) until you do a lot more research. As others have pointed out there are some problems with some of the criteria you are looking for (for example in terms of how they may impact privacy or scaling).
I suggest you start by looking at this site with 100+ Q&A already
https://monero.stackexchange.com/There are also 30 or so questions comparing Monero to other alternatives based on some of the criteria you specified:
https://monero.stackexchange.com/questions/tagged/cryptocurrency-comparisonIf you have more questions, please ask them on Stack Exchange!