Expert Gardener Hand Held Seed Spreader

Is the expert gardener spreader's number setting good or compatible in using with the branexpert gardeners bag of lawn weed control granule herbicide?

How well does it work for grass seeds? Some reviews said it is great, but others say it is worthless for seeds. which is right?

How wide does it spread - I need to do about 400 feet 3 feet wide -will this work?

How far out front will it project fertilizer?