>>283455826
1) I am of the opinion that you should watch a different season if it's your first, just to get a feel of what Precure is about, because I feel that HS is presented differently than the average season, and it was clear they had wanted to do that as an Anniversary season. But it's not like you're missing out on context or plot points or whatever so just go ahead if you want to. Also, as a 20th Anniversary season before the ED plays a past Precure will greet with the viewers with a message, in case you'd like to go into the other seasons as blind as possible.

2) Other than season movies, there is a series of All-Stars movies. Typically a season has one of each until a certain pandemic threw the movie scheduling off. For HS, there are no season movies though there is a super special 20th Anniversary All-Stars movie instead of your typical All-Stars movie which I wouldn't recommend watching just because you'd have no idea who the other Precure teams are. As for guest-starring in episodes no it's not a regular thing they do on every season, just on special occassions.