GCC-High and Planner/Project for the Web/Teams/PowerApps/Accelerator

I have so many questions and I'm not entirely sure where to post or what to start with. I know this is a lot and I thank you in advance for whichever parts you can answer or point me to the correct answer. I have already been digging (and digging…) through KB articles, but it's a lot to go through and my technical skills are more of an understanding (it's why I'm a PM ^_^). If I am unclear in anything please ask and I'll try to rephrase/explain.

• Company is in a GCC-High environment. 
• Team:
• Dept Head - needs all the access necessary to manage all programs and report to C-suite
• PM1 - me - needs all the access necessary to manage the platform and projects
• PM2 & PM3 - needs access necessary to manage their own projects, create reports, assign resources
• No PowerBI and least amount of/no admin necessary

• I (PM1) am a program manager, helping implement/improve PM processes
• I have the Plan 3 license, but can be moved to the Plan 5 license
• I also have a PowerBI premium license
• I think we're all on a G3(?) license? I can't seem to find the page to login to and check again
• industry is manufacturing
• We do have "vanilla" D365 (and apparently D365 Project Operations was unusable)

________________________________________________________________________________________________________________

Here's what I have to work with:

• Project Desktop/Project Online (prefer to get rid of this)
• Project for the Web (referred to here as PftW)
• "old" Planner
• Planner Premium is (by all accounts) not currently available for GCC-H
• Teams
• PowerApps (default environment)
• I really want Accelerator, but am still watching videos to try and figure out how to work it

Most important stuff I'm trying to figure out:

• I will be the System Admin for our PM platform (Project for the Web, Planner, Project (PowerApp), Accelerator)
• What security roles do I need and where, especially in PowerApps?
• I can't find a screenshot of what's available so I have no idea what to research for
• will those security roles also cover PftW/Planner?
• Would I need any other permissions for Accelerator?
• Teams Apps:
• is the Project app in Teams available for GCC-H?
• everything I see says yes, but I can't find it in our "add-an-app" so I just want to make sure it is before I ask IT to go look again and enable it.
• Where does this pull from? 
• Will it pull from PftW and planner? (since ours are kinda separate, sorta)
• Accelerator:
•  IT would obvs need to deploy, but would each of us on Team be able to use it or it would need to be added for each user?

• Resource Management
• Groups/teams:
• Best way to assign a team (or sub-team)
• I cannot make groups, IT does not want to make more groups/teams
• We were able to get 1 team created with ALL members who would be assigned at least a task
• Can I create groups/teams within the resource management console in PowerApps that doesn't require any other resources (like an email/teams/sharepoint, etc?)
• My understanding:
• In PftW, you have to assign a project to a group. All projects are assigned to Group 1 (everyone)
• I want to:
• Assign a task to a "sub-group" like "Production" or "Engineering", but only one group can be assigned to a project
• Current workaround: make a new drop-down column OR use labels, but unsure if this would pull correctly into PowerApp/Accelerator
• Do I need any special permissions/security roles to manage resources in PowerApp?

If you made it this far, I really appreciate it. I thank you for any help/insight you can offer.