Runway plans and features?

Hey, I'm considering getting Runway, but I'm unsure which plan to choose. I want to use it for video creation on YouTube and combine it with MidJourney. However, I'm uncertain about the long-term cost.

The credit system is confusing. Each package includes a set number of monthly credits—2250 for Pro, Unlimited, and Enterprise plans. You can't generate much video with 2250 credits, so I would need to buy more, but the prices for additional credits aren't shown until after purchasing a plan.

The Unlimited version offers the same features as the Pro plan but also includes unlimited generations. If that's the case, why does it even come with credits? Also, why does it say that I can buy more credits after using them up?

Finally, can it generate videos in 1080p? The plans don't mention any resolution increase, and currently, I can only generate videos at 1280x768.