I've never heard of anyone doing that effectively: "When are you free? Let's plan a time for a phone call!" Makes the call sound like a super big deal. Both parties will be nervous about it. A call should be a fun, light, spontaneous event, not some planned ordeal.
If she doesn't answer, that's fine. Leave her a great, strong, sexy, fun voicemail for her to listen to.
The chick in question dodged your call, said she was busy, then ghosted you over text. If you're taking it at face value that she was 'busy' and you should've 'scheduled a time', you are getting entirely the wrong message from her. The right message is "I'm not interested, so no matter what way you try to reach out to me, I will ignore you or consider it an inconvenience."
2. -- yes, or try this.
3. -- make a very strong first impression, have a couple of strong phone calls, then invite her. If you did your job right, and she is interested, she will come. If you didn't do a good job and/or she isn't interested, she won't enough.
4. -- phone calls are an inconvenience, but the more she likes you the more she will feel excited you are calling or she will feel like she has to talk because "OMG, it's SZ! He is so cute!" At which point, either she will talk, or she won't because she's too nervous, but she'll feel bad and feel like she did something wrong (by ignoring you). That said, if you can get her out with texts, get her out with texts. It's easier/faster/simpler. Phone calls are mostly for women you screwed up the initial approach with, screwed up something else after the approach with, have waited too long to set a date up with and now they've forgotten you, or you have some other reason to need to rebuild trust and interest, or else address some difficult issue text is taking too long to address.