I use a text forwarding tool for my browser. I'll be at my desktop and get your SMS messages, including the ability to reply. They can call... but then I get to say "I'm not at my phone, what's up?" - whether my phone is nearby or not.
Good question, I think that depends on your phone/settings. If it's just silencing, probably not as to the caller it will keep ringing until VM picks up. If it's declined, that may go straight to VM and the caller may notice a shorter ring and connect the dots.