Has anyone complained about you texting or calling them too much?

You seem to have a good agreement with your sister (i.e. her calling when she can) and with your best friend (i.e. letting one another know if either one is not in the mood).

Unless you are placing expectations on people (be it sister, bf or brother) or crossing their boundaries, I don't see a problem...

If you want to be sure you can always ask them 'hey, am I texting/calling too much?' or something like that.