I think that is a very normal plating on the glass of microalgae and its what would be expected for the bioloading of the tank.
mine looks similar each week if its not cleaned
actually I might not recommend peroxide for that until it morphs to different genera on the rocks but your tank is new enough you can arrest that process if we are lucky
I would use a razor blade epoxied to a wooden dowel as a long angled scraper and keep the glass clean.
regarding the oil slick, thats proteins collecting on the surface, its a reflection of the organic loading into the water column from the life forms in the reef. you would have to resort to old school extra skimming, + water changes to defeat that
sure some will recommend better circulation to distribute it throughout the tank, but thats a bandaid, removal is what you want. Running GFO in a filter would be indicated for this tank and its bioload for sure, but be careful not to overdo it thats for sure. The tank is really sharp looking and there's time to fix the nutrient issues before they migrate onto the rocks, that happens at about the year mark in most tanks like this.
The green deposits on the glass are probably best cured with manual removal that will be timed based on how the tank processes the feed and waste the fish require. It may be more than weekly...at least razors on dowels don't scratch.
In my tanks where the drain is easy I just wipe over those deposits with 35% peroxide and it cleans them off with no scraping, but your tank isn't as easy to drain so we ought to look into some additional nutrient controls on this tank due to its size and fish loading.
If you are already using phosphate binders, we'll need to up that as this is the early stages of eutrophication but it hasn't taken hold yet.