2) Plan on a 2 x 16gb ddr4 kit. Photoshop can use ram as workspace and my reading says more ram is better for photoshop.
3) Unless your budget is very limited, where the extra $25 or so makes a difference, I would buy the CPU with integrated grapnics. It is easiest to test with the gpu on the motherboard, and on occasion you will have graphics issues that can be diagnosed easier if you have an alternative graphics adapter.
Also, integrated graphics has Quick sync which may be of use to you.
https://www.intel.com/content/www/u...uick-sync-video/quick-sync-video-general.html
I am no expert on this so you need to do some research.
Most lga 1700 motherboards will support pcie 5.0 X16.
If you go to newegg and filter on lga1700 and pcie 5,0 you will get a list of such cards.
On any selected motherboard, go to the motherboard maker's web site and access their support tab.
It will list all of the supported processors.
In general, any lga1700 motherboard will allow a I9 to be connected.
But, the issue will become how well.
A I9 can draw a lot of power when running to it's potential.
Look at the image for the motherboard.
Look for a motherboard with a robust set of cooling for the vrm's.
You might also look at the 4/8 pin EPS power connectors.
Good overclocking boards that can handle higher current will have two 8 pin connectors.
Here is an example of a basic B660 motherboard:
https://www.newegg.com/p/N82E16813162042?quicklink=true
A more advanced Z690 version with two 8 pin connectors:
https://www.newegg.com/p/N82E16813162042?quicklink=true
On selecting a processor, get acquainted with the passmark ratings.
For example, a I7-12700K has 20 processing threads. 16 of which are high performance and 4 are lower performing. The total passmark rating is when all 20 are fully utilized
The total rating is 34164. For games and overall quickness, there is a single thread rating which is 4049:
https://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-12700K&id=4609
A more modest I5-12400 processor would have 12 threads and a rating of 19538/3531:
https://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i5-12400&id=4677
What is your current processor?
search google for "xx-xxxx passmark" and your first hit should be the link you want.