Hidden grottos should be easy enough. Just make a map for them, and make events on trees to enter them. You can look at example events like Kurt on Route 1 to see how to make them refresh over time.
Russel grass and dirt could probably be done with events, but most likely would require some scripting. I'll look into it a bit because I think its a cool thing to include in a game. Most of your other questions...CHECK THE WIKI. seriously we've told you multiple times. If theres questions not on the wiki tell me what they are and I'll do my best to help
I am not a scripter, I need help to get started. And my questions are not in the wiki.
I dont ask for day night battles, I ask for events which dont happen at day and are just seeable in night...
I think you are confusing eventing and scripting. Scripting is done in the script editor. Events are made in the map editor when in the events tab.
To make an event only show up at night is really simple. Just make an event, and in the top left area where it says conditions, check one of the Switch boxes, and select the switch that says something like DayNight is Night. It looks a bit different than what I typed, but there are about 5 switches like it, that all have different endings like isNight, isDay, isMorning, isEvening etc. this way, the event will only show up if the time is day, night, morning, etc.
However, if you haven't set up Metadata for the map, time won't change on it.
Again: I dont know how to make events... So telling me to read the wiki is useless because it wont help me...
Which is why I suggested googling tutorials on RPG Maker XP so you can learn. I am putting the tutorial up right now in Tutorials and Resources. It might take a while.
I was kind of harsh with you and I'm sorry for that. Hidden Grottos ended up being a bit more complicated than I originally thought, but I was able to figure them out after 15 minutes of trial and error. There is actually a bit of scripting needed, but it is really simple and my tutorial will be easy to understand.