Ah, the juice question. I have gone through phases of juicing greens, especially sprouts. Including some 7 day "fasts" using feesh veggie juices, lots of water, and fresh live sprouts. Did so not as a vegan or anything close to it; more of a "cleansing" regimen. Found the effects very beneficial. The protein contribution of the sprouts helped prevent lean tissue wasting.
Sugar levels of green is obviously much lower than fruit. My gut sense is that the overall wellness advantages of a daily 8 ounce glass of freshly juiced greens (say celery, spinach, cucumbers, dandelion, sprouts) with a carrot and some beet tossed in) would far outweigh liabilities of added sugar. For one thing, that drink would easily replace the daily multivitamin. Plus, that concoction is very liver and lymph friendly.
That said, it's winter and cold and the only way I would consider that regimen now, is to spend a week in some tropical climate. Top of list: Maui, Kauai.
Overall I keep unjuiced green veggie content high in my diet: Paleo/Primal with plenty of meat protein and fat. I haven't used juices for a while. Fruit juice is verboten for me at this point. Open to green juices, just not a high priority. I use various herbs (milk thistle et all) for liver support, on a kind of maintenance/prevention model.