Is it small enough to count as a carry-on?

Yes. At roughly 45 cm wide and 29 cm tall it is built as a carry-on weekender and fits most overhead bins and under-seat spaces. Check your airline's exact limits before a strict-budget flight.

Does it have a shoe compartment?

Yes, there is a dedicated shoe compartment, plus a wet pocket and six compartments in total. That separation is the main feature that sets it apart from a plain duffle.

Can the shoulder strap be removed?

Yes. The shoulder strap is adjustable and detachable, and the bag also has carry handles. You can switch between shoulder and hand carry.

Is the bag waterproof?

No. The nylon shell is durable but not waterproof, and the wet pocket is the intended place for damp items. In heavy rain, expect some moisture to get through.

No. It is a soft-shell carry bag with no wheels or telescoping handle, so it is carried by the handles or shoulder strap. That keeps it light and foldable.

What can it hold for a weekend?

About two to three days of clothes plus shoes in the shoe compartment and toiletries in the wet pocket. It is not sized for a week-long trip without laundry.