Or you could just add the nibs now,and bottle in 3-4 weeks.Then sample it when you bottle it. Yes you could add some sugar when racking if you rack it to secondary also.You could probably rack it now if you wanted to. I would just add the nibs now and let it sit for a few weeks. Or just do it the way you wanted. I dont open my fermenters unless Im dryhopping or bottleing or sometimes rarely doing secondary. I usually have to have a good reason to secondary also like for doing a lager or if I were to use fruit in a mead or something. Like you Ive become more cautious about oxygen exposure the more I brew. I have a co2 tank now since being new to kegging so I can reasure myself if I need to and when I need to. Ideally though if you secondary you want to fill to the neck of the carboy that way you dont have to worry about oxygen or adding sugar for a little more co2 exposure. I think the main reason for so many infections is all that head space in secondary or people are opening their primary fermenters too much and getting nosey. Head space is ok in primary especially if its left alone til bottleing. Im still ok with opening primary to dryhop after a week or so without worry.