Can I weld this aluminum pipe, or does it need TIG welding?

Aluminum pipes require TIG welding for a clean, strong joint. MIG welding is possible but produces weaker results on thin-wall aluminum. Have your fab shop confirm their equipment before dropping it off.

Will the black finish hold up if I'm running this on an exhaust manifold?

The hard-anodized finish handles moderate heat well, but sustained exhaust-zone temperatures above 400°F will eventually dull or discolor it. For high-heat applications, ceramic coating or stainless steel pipe is the safer move.

What's the wall thickness, and will this support a turbo inlet or just small-diameter runs?

Wall thickness isn't specified in the product data—contact ModSupply before committing. Test-fit the diameter on your routing first; 3.0" works for most custom intakes and secondary cooling lines, but boost-pressure applications demand confirmation from your tuner.