It note" pack of 1" (sometimes "pack of 2"), does it mean 1 pair or 2 pair?

1 pair. The Amazon system sometimes adjusts the size expression of glove categories, which the seller cannot control and modify. In any case, all firefighter gloves form Intra-FIT are packed in "1 pair".

Can I pick up burning logs for the fire pit at camp?

No. Firefighter gloves are not meant to handle hot objects but to protect the hands from high heat, the air, otherwise referrred to as convective heat. They are not designed for direct contact / conductive heat.

Is the liner glued in all the way through the glove or just at the fingertips?

All through the gloves, so that they protect hands from physical and chemical harm without undermining the gloves' dexterity or tactility.

I have already a pair of structral firefighter gloves, should I buy an extra wildland firfighter gloves?

Structural firefighting gloves need to protect against more injuries than wildland firefighting. But field operations require more comfort and flexibility. So a pair of professional field gloves is more suitable for wildland firefighting operations.

These gloves are much more expensive than the 20~30 firefighting gloves on the market, what is the difference?

As a vital equipment of firefighters, meterial used, protection level, size fit, dexterity, all details are critical for you, the greatest firefighter! Cheap gloves don't meet NFPA standards, nor the needs of real firefighting operations.