If one is a devout JW and the devout one's parent is a professed non-Christian, is the devout JW to associate with the non-Christian parent? If so, what type of relationship is allowed according to JW teachings?
A relatively normal relationship. They would, hovever, be encouraged to preach to them whenever possible.
Are JW's allowed to assist an elderly non-Christian parent? Are they allowed to provide what the parent needs (within income limits)? Is the parent permitted to visit overnight or longer in a JW home? May a JW provide love, consideration, and caring (emotional and physical) to the non-Christian parent?
Yes. In fact, they are obligated to.
What about associating with other family members who are worshippers in other faiths?
That's fine as long as they were never one of Jehovah's Witnesses. Again, they would be expected to preach to them.
Are JW's forbidden to have meaningful family relationships with those outside of his/her faith? Are JW's forbidden to have any relationships with others who are not members of the JW?
This is where the line get's blurry. You are supposed to keep association to a minimum with those of other faiths, even of your own family. An elder might give you counsel for going on a vacation with your "worldly" relatives, but it's not something that will get you into any trouble. Of course, this all changes if one of your relatives was once babtized as a JW. If so, they are considered disfellowshiped and most contact with them would be discouraged. Of course, many JW's break this rule and get away with it.
The information I was given was that JW's are to associate only, on a personal level, with other JW's.
This is correct, but it is a grey area. Your own conscience comes into play here. Basically, a "don't ask, don't tell" policy takes place.