No good little filters. The ones in the cup are Pineapple. The ones on the glass are different.
Its safe to scrape em. Theyll come back but scraping them will chase them into less obvious places like the sump filters and rocks.
Sponges do appreciate silicates, unless you're intentionally adding silicates I would not worry about it. The streaks on the glass are just a different sponge type. Typically these types of sponges like cryptic/dark areas of the tank. Neither sponge type in your tank is harmful or prone to becoming invasive. Personally I always consider sponge growth in my tank a positive sign regarding the tanks bio-diversity.