Of the three you mentioned I’d only say that a chain breaker/riveter is necessary. I’ve used a few of them and the Motion Pro PBR is the best I’ve used by a wide margin.

Slack you can do visually, with a tape measure, or using a pretty cheap specialized tool. Same deal with alignment. Visual, or a cheap tool. You’d have to be pretty far off base for either to become critical, but if the tool helps give you confidence then it’s a small price for that peace of mind.

https://www.amazon.com/Motion-Pro-08-0470-Chain-Breaker/dp/B0050HJNW4

https://www.amazon.com/Motion-Pro-Tension-Setter-08-0674/dp/B077ZYZH3P

https://www.amazon.com/Motion-Pro-08-0048-Chain-Alignment/dp/B000GTVOJQ