On caddies: with the possible exceptions of when he had one of his sons on the bag, can anyone remember Jack Nicklaus ever asking Willie Peterson or Angelo Argea even for yardage or a club suggestion, let alone having a single Spieth-Greller type 'discussion' with them? Simpler (and I'd suggest kinder and more generous) times: Jack paid them a weekly salary + a percentage of the winnings, and in return asked of them almost nothing at all.
On range finders: AG is probably right, and I should probably get one soon. But in the meantime: when I'm in the fairway I do pretty well with the 100-150-200 yard markers, and when I'm way off the fairway I use the 2 club rule, ie I estimate what club I need, then realize I need one club more, and then I factor in my unconscious pride and ego and add one more club on top of that -- if I first think it's a 7 I know that I should use a 5 iron instead!