You will want to wait about 30-45 days prior to planting after an application of Southern Ag Brush Killer.
Although a triclopyr herbicide such as Southern Ag Brush Killer may control goatweed, this herbicide is not labeled to control this plant, nor is it labeled for use in home lawns. If you are referring to goatweed (Scoparia dulcis), then you will likely need to spot treat using a non-selective herbicide like RoundUp QuikPro. If you are referring to goathead/puncturevine (Tribulus terrestris), then you can use a pre-emergent called Surflan to prevent this weed in warm-season turf like Bermuda and around many established ornamental plants.
To kill stumps with Southern Ag Brush Killer, you will apply the undiluted product with a paint brush or backpack sprayer to completely cover the freshly cut surface. The exact amount will depend on the size of the stump you are treating.
Southern Ag Brush Killer is not labeled to control Nandinas, also know as heavenly bamboo.
You can use RoundUp QuikPro at the highest listed usage rate to help eliminate bamboo. You will be required to cut the bamboo down to a short stump and then apply. It can take several applications to achieve the desired results.