This law isn't about keeping people safer, whether you were on your phone or not the officer has the right to search it (apparently). I imagine the motivations for this law is the same straw men they always are: drug dealers, illegal activity, child pornography, etc. etc.
> I also don't want some random police officer rifling through my private text messages, e-mails and voicemails for the purposes of seeing if I should get another ticket.
I don't even think it is that clear cut; if the officer pulled you over, he already has a reason to ticket you. Looking through your phone isn't going to make that better/worse unless you are involved in illicit activity and they find evidence of that on your phone. Then worse :)
> Additionally, I often make short trips for lunch (.1 miles or less). If a police officer does go through my phone, how is he to know I didn't send that text just as I got in my car before I left Wendy's to return to the office?
You don't need to worry about this (not what the law is for).