Final Fantasy 15 – Do Ignis’ Stats Change at a Particular Point in the Story?

Wait Mode skill tree appeals to a Tactician whereas Active Mode appeals to a Strategist and the benefit of spending AP in WAIT MODE is great should you find more comfort in a tactical role.

The AP in wait mode is designed to give players the same scope of information afforded in Active Mode, standing still.

For example, on PS4 Libra is activated with R1 (RB in XBOX), but you have to select the target and you typically only have a brief moment you can check Libra during combat. In WAIT MODE, you can be more precise in your actions because you have time to plan while you do not move.

As long as you don't plan on playing in Wait Mode, you're fine without using AP in the skills. If you do plan on it at some point however, Wait Mode is weakened unless you use the AP. Fortunately, the AP required is minimal compared to other skill trees.

You can play Final Fantasy 15 without watching Kingsglaive and Brotherhood, however this Reddit post does recommend that you watch Kingsglaive and Brotherhood to gather back story and context

I strongly recommend watching Kingsglaive and Brotherhood before starting the game.

Call it a failing on the part of the opening but I felt the game doesn't do a very good job of easing you into the story and who is who. It kinda just feels like your thrown headfirst into Noctis's journey without any kind of context or backstory save a scene or two in the opening scenes.

Don't get me wrong, I am loving the game but I couldn't believe how much backstory I would have missed if I had not watched Kingsglaive and Brotherhood. They really should have included them along with the standard edition of the game as they are kinda crucial for getting up to speed on what's gone down and who the main characters in the game are in terms of their personalities and their relationships to Noctis.

The wikis Kingsglaive and Brotherhood also contain developer comments towards the movie and anime and state you can watch them independently without playing the game.

Kingsglaive: Final Fantasy XV is a feature-length CGI film set during the events of Final Fantasy XV. It was officially revealed during the Uncovered: Final Fantasy XV event, and is 110 minutes long. According to developers, one can enjoy Kingsglaive: Final Fantasy XV without playing Final Fantasy XV, and vice versa. Experiencing both tales, however, ensures a deeper level of appreciation for them, as they are intended to complement one another.

Brotherhood Final Fantasy XV was conceived by marketing producer Akio Ofuji and the director of Final Fantasy XV Hajime Tabata, as a method to introduce the game's main characters and to help people better understand the game's character dynamic. Prompto in particular was subject to scrutiny, as he had ranked low in fan polls. Tabata has stated that while a typical role-playing game gradually assembles its cast, the heroes of Final Fantasy XV are together from the start. Brotherhood Final Fantasy XV shows how Noctis and his friends came together; developers hope the series would allow fans to familiarize themselves with the characters before playing Final Fantasy XV.