I had a similar issue. Went out for 4 months, came back for 1 month and then went out for another 4 months. During this time I had an active business here in the US - paying taxes like 941 during my absence. I maintained residence with a friend and paid him some rent - had a letter from the friend. Plus paid personal taxes, had credit cards, cell phone, renewed drivers licence when I came for a month. I even had a reentry permit.
Even though I had all of this - they still questioned me about residence + reason for going abroad for so long. The whole application got approved though - but still. I don't like to be questioned - period. Because I wanted to be as brief as possible I only told them about some of the ties I had. For example - I did not say anything about reentry, bank accounts in the US, about the fact that I had an active business in the US, that I renewed drivers licence, paid taxes.... Mainly talked about reason and the fact that there was a residence maintained - this is all IO was interested in.