I completely agree with the fact that there are not enough love scenes in the latter part of the film. I am not necessarily meaning sex scenes (although, of course, they would be welcome!), simply explicitly showing a little more love.
This is because, at first glance, it seems that their relationship has become more friend-like than lovers, however looking deeper, a long term relationship does grow into an easy comfort and becomes more about making love than furious, insatiable lust. I would therefore have loved to have seen them grow as a couple, i.e. holding hands etc. That being said, we never saw them share a cigarette or drink from the same bottle at the start of the film. That comes later, during the "miss you so much" scene at the lake (or loch as we Scots say!).
I firmly believe that the opposite of love/hate is indifference so their blow up at the end and Jack supporting Ennis shows the undying love and affection that still exists between them.
Lastly, I'm sorry to hear about your friend's loss Artiste. I'm sure I speak for all when I say pass on our condolences.
Sandy