Apparently, the biting was enough for them to put him up for adoption to 'protect' their baby to be. I emailed with her extensively initially, before and after I picked Tucker up. It was always that he had only been one person. (Mind you, she also told me Tucker could only go 5 or 6 hours before he had to go out to take a leak, I've had him go up to 14hrs now (example: 7pm until 9am next morning, not 14 hours of awake time).
Typically, when I have company I pick him up and hold him until the person or the people are inside and settled. I use the gate for pizza deliveries or for company that will only chat at the door. There is a problem with the bars, though. He's more aggressive when behind them so I've stopped using that as a method of isolation while people are over. If anyone comes near the gate, he growls at them and is especially menacing if anyone leans over the gate or reaches over the gate. He even growls at me when I reach over. He certainly doesn't like to be trapped in a corner! The gates, unfortunately, isolate the kitchen, which is a high traffic area - especially when friends are over. He stays on the balcony during the days, so if I have company and am worried about his actions, I just put him out there and put the blockade thingy in the doggie door.
With time you'll get to know Tucker a little better each day & it will be easier to manage. We'll get there! Feel free to PM me with any questions since I too have had to get "creative" with my little girl 
It would be useful to know more about this dog. Has resource guarding been an issue in the past? Has he bitten either you or your wife before? (a real bite, not playful nipping). Or anyone else? A dog that isn't used to children may be fearful of their loudness or quick movements. Perhaps you could do some socialization work with him, e.g. hanging around places where young kids congregate to accustom him to their noise and activity. Obviously not allowing any interaction as you are unsure of his behaviour. Dogs react differently to newborns. In my experience bitches are more likely than dogs to be tolerant, but it is very much the individual dog's reaction that counts. People have been blindsided when their supposedly tolerant and gentle dog turns out to be hostile to a young child. Bottom line, no dog should be left unsupervised around young kids, so in any event you would have to monitor his behaviour carefully once your baby arrives.
On a personal note, of the five Basenjis I have owned, two bitches were entirely reliable with kids, the other was tolerant as long as they respected her space. One of the males adored children and was curious about them, the other curious but uncertain and would react to fast movements. I did not trust him and controlled any interaction closely. IMO, he would have bitten had he felt threatened. And kids, especially babies, tend to grab and pinch, ears, tails, whatever. Caution is always the safest route.
