You can make Radha Krishna appear in this in picture for B.G. Ch. 5, vrs 4-6. Radha Krishna includes Laksmi Narayana. Then the picture will be more clear to the reader, as you have mentioned. The bhakta worships the Deity in form and the Sankhya meditates on the Deity in the heart, so the Deity is there in either case, so they are the same. But impersonal meditation is not bona fide. Personal meditation is bona fide. So one has to attain any state by Bhakti. Without bhakti, there is no chance of perfection, either to merge with Krishna or to become an associate. Bhakti must be there. But the sort of Bhakta who is trying to merge, that is not pure bhakti.
Why just 25 rounds? You should chant as many as possible. Real Ekadasi means fasting and chanting and no other business. When one observes fasting, the chanting becomes easier. So on Ekadasi other business can be suspended as far as possible unless there is some urgent business.