All very valid questions. For picking altcoins I use coinmarketcap.com to cross-reference altcoin BTC-values with the BTC pumps. I’ve noticed that the coins like ETH, LTC, and especially BCH are extra-sensitive to those pumps. Maybe Bitcoin Gold, too, but I haven’t had the time lately to go see for myself.
As for “when the pump is over” that’s a combination of 90% luck and 10% technical analysis. You can find historical support and resistance lines. From a technical-analysis perspective, these lines signify prices where a currency will get a lot of buys or a lot of sells. You can go to tradingview.com to check out other people’s analysis, too. Like I mentioned in the article, it’s impossible to get it perfectly. Even if you hit a bullseye on the Jan 2 pump, the delayed Jan 5 pump brought prices back down again.