(Incidently I cant help wondering why, if Jack was so in love with Ennis and wanted to be around him why he didnt just move up to live around Ennis anyway ... by the time Ennis was divorced he would have had more freedom anyway and by doing so Jack could have taken more control of the situation by himself?)
With regards to the last part of your question that is ultimately a very moral question and I dont really feel qualified to pass a overall opinion on it (Indeed regarding the whole thing I'm not trying to pass a moral judgement on anything but to rather suggest how I perceive the situation to be). Fundamentally its the same question that straight couples, who are going through divorce, have to ask themselves all the time ... to stay together for the kids or to move on... However, regarding Ennis and his daughters, while in the early years I can see how that argument would stick in the later years Ennis was divorced from Alma ... the girls were grown up ... and after his argument with Alma (you dont go there to fish) he didnt see them for a prolonged period of time anyhow. Even saying that, on his say so Jack would have moved up to live with to him so that, in effect, Ennis could have had his cake and eaten it. My feeling is that Ennis' primary fear was his own homosexuality and that he used his daughters as an excuse not to move in with Jack. Jack on the other does appear to be willing to sacrifice important aspects of his relationship with his son for Ennis (again I'm not inclined to suggest whether that is morally good or bad) ...
Basically what I'm trying to say is that because of Ennis's fears he was unable to provide Jack with what he needed (and hence the love he felt he needed) for a relationship. It appears that (to me) the last scene Ennis had finally come to terms with his feelings (Jack I swear .... (I love you - I presume)) and that he would be prepared to move in with Jack were he to miraculously reappear. ... I'm simply trying to suggest my interpetation of their feelings rather than passing a judgement on whether those feelings are admirable or not.
Anyway ... sorry that this is so garbled ... these are very deep emotions and I sometimes fimd them hard to interpret properly :-s
Sorry it's been so long since I've been around - also going to be on vaca for two weeks (lucky me, I got to work 17 hr days this week, LOL!)
Anyway, I think the answer to your first item (which is parenthetical) is Ennis' paranoia - having Jack around would have been too much of a temptation for Ennis (from the story 'can't hardly be decent together' - from story and film, 'this thing grabs a hold of us' and 'ain't no reins on this one.') - especially after his confrontation with Alma in the kitchen Ennis would have NOT been comfortable with Jack being that close, I'm thinking.
But your thought goes deeper, and I think appropriately so - I'm just beginning to pick up on this from the IMDB boards. Basically, Ennis is so homophobic that he's desperately, (pathologically?) afraid of his desires.
I might be willing to buy this, it'll take some thinking on.
And insightful (especially in terms of the story) about Ennis perhaps using the girls as an excuse, particularly after the divorce, although both the film and the story still seem to show an Ennis who really has no desire to expand his horizons by traveling or leaving the comfort of the familiar. Film Ennis was a more devoted father LATER in his life than story Ennis, which does pick at my theories that Ennis was somehow morally "superior" to Jack because he was gonna stay around for his girls . . .
Of course, in the film, Jack does suggest Ennis move to Texas when Ennis actually voices his paranoia to Jack; naturally Ennis responds with scorn and derision to Jack's suggestion . . .
I'm from a probably unpopular camp of thinkers now a days who actually believe that, absent abuse, it's generally better for parents to stay together for the children's sake until the youngest hits 18. Posting that though over at IMDB got me more abrasive responses than anything else I ever posted there - many from folks who sound like they were pretty hurt by their parents' conflict - but exceptions don't necessarily break a rule.
I would much rather Ennis kept Jack in his "sights" right after BBM and neither of them married; failing that, I would have liked them both to stay in the marriages (which Jack does, but Ennis doesn't, BUT I have to believe Jack would have divorced Lureen in a moment if Ennis made himself "available") until the youngest child of the three was 18 - then, have at it! But many people (understandably) feel they should have been together right after they reconnected. My problem with that view is it really makes Ennis the 'bad guy' and I'm not feeling like I want to saddle him with that - as you say, stickler, they are both victims, but to some extent, of their own poor choices.
Is it the Fine Young Cannibals who sing about if you've ever fallen in love with someone you shouldn't have fallen in love with?