The test that matters most is whether the name survives being spoken. Somebody hears your name at a networking event or over the phone, has no way to write it down, and types it from memory two days later. That single scenario eliminates most bad choices. Creative spellings fail it, because the listener types the ordinary spelling. Numbers fail it, because nobody knows whether you meant the digit or the word. Anything requiring you to say "with a K" or "no vowels" has already failed. Read your shortlist aloud to somebody and ask them to type it without seeing it, and watch what they get wrong.
The .com question is worth settling plainly. For a business selling to the general public in the United States, .com remains the default assumption, and a meaningful share of people will type it regardless of what your card says. That does not make other extensions unusable, but it does mean you are accepting some leaked traffic and a small credibility cost. If your ideal .com is unavailable, adding a location or a descriptor usually beats moving to an unfamiliar extension. In Las Vegas the city name works well in a domain, because a large share of local searches include it anyway.
Screen for conflicts before you commit, because availability at a registrar tells you nothing about whether you can legally use it. Search the federal trademark database, search your state business registry, and search the name in quotes to see who else is using it. A domain being available and a name being safe are different questions, and discovering the difference after you have printed signage is expensive. This is general information rather than legal advice, and a name you intend to build a brand around is worth a professional search.
Then handle the practical parts most people skip. Register the domain in your own name or your entity name, never under a contractor account, because whoever holds that registration effectively holds your identity. Turn on automatic renewal and registrar lock. Add privacy protection so your home address is not published in a public database. Register the obvious misspellings and the .net if they are cheap, and point them at your main site. And use an email address on the domain from the first day, because a business address on a free provider undercuts the credibility you just bought.