Xbox series x not loading games and taking long to open them

In this case, our suggestion here, attempt a Soft Factory Rest Xbox Support by selecting the following:
Reset and keep my games & apps. You should use this option as your primary choice when troubleshooting. It will reset the OS and delete all potentially corrupted data without deleting your games or apps.

That makes sense...so let me ask you this...will “not optimized “ games work any slower if I run them from an external hard drive rather than the actual internal drive?

They would load the same on the Series X as they do on an Xbox One.

But, take an un-optimised open world game such as Assassins Creed Odyssey and run it on the internal drive of the Series X compared to a USB mechanical drive and the difference is night and day. Fast traveling on the world map on USB mechanical drive takes around 40 seconds. On the Series X it's less than 10 seconds!

Webpages take far too long to load, the more threads i open in new tabs the time it takes for them to loads grows exponentially.

You can transfer content between the two sure. You would do it the same way it can be done on the current Xbox One S and X.

You may not be able to transfer everything as the expansion is 1TB and your hard drive may be larger than this. You won't need to transfer everything anyway as the hard drive can still load Xbox One games, it just won't be able to load Series X/S games.

The loading performance you'll get will vary per game. With Open world games benefiting the most.

I have a gaming PC with a modest speed SSD. On Assassins Creed Odyssey it takes 6 seconds to fast travel between locations in the game world. On my Xbox One X it takes 40 seconds!

Due to how Microsoft is going into this next generation Xbox Series X games will also be released on Xbox One, as to not leave anyone who can't upgrade right away behind.

On the flip side to this however any game that comes to Xbox One before coming to Series X will get you a free Series X upgrade with Xbox Smart Delivery. (so long as Developers & Publishers choose to take advantage of it)

I hope this information helps.