if you are outside the forum and let's say for example, you don't know the gambling board in this forum, you can indeed check it via google search. because if the are existing allegations or has history of scam accusations, you can easily see it. even trustpilot feedbacks are worth to read as some are legit reviews. however, if you are in doubt, you can always double check it with other references or sources like in this forum.
every gambler has their own preferences when it comes to their games, so this question is quite subjective as it depends on the player himself. but as much as possible, better choose a casino with less to no existing allegations. you are using your funds, so better secure it because no one will.
Yes its a must to conduct our own research even the casino is seems legit or most recommended. Make sure there's no existing scam accusation (it can be search in google or here in the forum) to be safe that you're dealing with the casino that has no past/present issues. Since we have different preference on the games that we want to play, just remember to only gamble in the type of casinos that has good reputation and trusted by many gamblers.