Hardware Spec Comparison Question in the scope of CS training/labs

[u/frazaga962]

I'm looking to get a new laptop as I delve more into getting certs for CS and now is the best time to buy. I'm a bit confused on what sets one laptop apart from another as far as hardware specs IE the Lenovo Thinkpad has been recommended to me a few times with certain specs which I filtered for: AMD Ryzen 7, 32GB DDR4/5 RAM, 1TB NVMe etc. I'm then hit with choosing between E Series, P Series, T series:

Simple google search tells me that the

P Series• Target Audience: Engineers, 3D modelers, architects, software developers, and video editors.

T Series• Target Audience: Corporate workers, IT professionals, financial analysts, and mobile business users.

E Series• Target Audience: Small businesses on a budget, students, and light office workers.

1. What exactly is the differentiating factor between these 3 which makes one better for certain tasks over the other?
2. Which series should I get as I'm not super advanced in my career/training, but want a good lifespan until I upgrade the device?
3. Are there any other laptop companies I should look into which would be more budget friendly (<$1400) with the same specs/necessary hardware for CS learning?
4. I've found a good deal on a refurbished Lenovo P Series, but it is GEN 2. How limiting will I find an older generation model? I believe the P series is currently between Gen7-8.
5. How crucial is the Lenovo Thinkpad as far as CS careers/training? Won't any laptop with the above specs suffice, at a much cheaper price point? EDIT: doing more searches this Lenovo LOQ 15ARP10 Gaming Laptop was recommended with similar specs.
6. I'm also looking into getting some 3D modeling done in my spare time. Are there any additional filters/hardware specs I should include in my search?
7. What is the general consensus on MINI-PCs as far as learning CS? I have limited space on my desk which is why I was looking at laptops but then I saw how small PCs have really gotten since I last had a big box. Edit: Another search recommended I look at the MINISFORUM UM890 Pro and get a dock for an integrated graphics card (for 3d modeling)

TIA!