ASUS ROG Strix GeForce RTX 3090 OC + Razer Core X Chroma Compatibility

Hi everyone! First time I am posting here. Thanks for your help in advance. I'm a motion designer. I have a workstation and a Razer Advance (2020) to work on the go. I have travel planned, and I have some contracts to fulfil. I'm mainly doing 3D work now, and I need a GPU for rendering and helping in the workflow. So I plan to get a Razer Core X Chroma and stick my 3090. I will have to replace also the PSU for the one I have in the workstation because the PSU that comes with Chroma is 2 x 8 Pin and the graphic card is 3 x 8 Pin. The graphics card fits pretty tight. Graphic card 12.53" x 5.51" x 2.27" Inch 31.85 x 14.01 x 5.78 Centimeter Chroma 12.99' x 6.29" x 2.36" Inch 33 x 16 x 60 Centimeter Please see below the parts I'm talking about it. Graphic card https://www.scorptec.com.au/product/graphics-cards/nvidia/85441-rog-strix-rtx3090-o24g-gaming?gclid=Cj0KCQjwqc6aBhC4ARIsAN06NmM4r97wvy_aD3cmX8XQ9mfPQxQAQOMJ4dDLXedXi-77mv5BxKUVlI8aArGPEALw_wcB PSU https://www.scorptec.com.au/product/power-supplies/atx/86920-sst-st1200-pts A couple of questions

• Can I replace the PSU, and will my PSU fit?
• Should I be worried about overheating because of the card size?
• Do you think something like that will work at all?

Let me know if it makes sense. Thank you so much again, Denys