I'll take a shot at this ... Of course, the opinions offered are strictly my own.
1. When wives are widowed, and they wish to remarry must they stay as a group or find seperate mates?
Unless you know some scripture on the topic that I don't, that would seem to lie within the purview of individual choice. The wives certainly are free to set up a united front and say, "We come as a 'package deal' ", and that would of course be very nice. However, they've been loosed from the bond to their husband according to Rom 7:2 or so, right? That would seem to give them individual freedom. Each had her own individual marriage to their common husband.
Besides, what if they disagreed as to who to accept as their next husband? Or whether to? Who would decide? Individual choice seems best, though others may well disagree.
2. In a case where one of the wives and the husband die is/are the remaining wives condisered the parent(s) of all the children?
Again, individual choice might well be in play. Certainly, at the very least, the situation would be the same as if a step-mother was involved. A very real relationship does exist. As to the legalities, that is likely to have courts and relatives in an uproar UNLESS the husband and wives have made their wishes and intentions very clear through the appropriate legal documents -- wills, trusts, contracts, etc. Doing so makes responsible good sense whether in a mono or poly marriage. Just look at the fiasco surrounding Michael Jackson's kids.
3. What are the "vows" used in a wedding for plural marrages?
Much the same as in any other, I would think, with the exception of leaving out "forsaking all others" on the man's. When my wife and I married in an SdA church, I explained our belief to the Pastor, and instructed him specifically to leave that clause out of the vows, or I'd say, "No!" loudly and clearly. He handled it by using the minimal vows something like a justice of the peace might use, then having us read out our own vows, which worked pretty well, except that we both kinda broke down while saying them.
Then he said, "You may kiss the bride." and I came out with a good loud "Woof!" before doing so thoroughly. Several in the audience who knew our habit of conversing in woofs and meows gave good loud Meows during the, um, proceedings, to the general merriment of all.
So, I guess, my opinion is to have at it, and have fun, and not get too hung up on a formula.
4. Am I correct in saying that you don't believe plural marrages are a mandate for everyone?
Correct. First of all, scripture doesn't mandate it (with a very few potential exceptions). Secondly, demographics wouldn't support it unless we killed off significantly more males, and I'm not volunteering either myself or any of MY sons for the guillotine.
5. When the husband no longer can have sexual relations may he use ED drugs?
Back to personal choice. I suspect his wife or wives would rather appreciate it.
Of course, there are lifestyle changes that may well reverse the condition and replenish the lead in his pencil more effectively. An extended fast, like 30-40 days, happens to be one of them. Mineral, vitamin, and herb supplementation are others. Moving to a primarily or exclusively plant based diet is supposed to help. I know a man recently turned 90 who is still, um, active, if less frequently than in the past.
6. Do any of you live in any type of "compound?"
Like the Branch Davidians, or FLDS in the Big Love movies? So far as I know, "Not only NO, but ..." ... you get the picture. We're too much individualists, who have arrived here through our own thought and study rather than through sublimating our wills to those of another self-appointed prophet.
Having said that, some of us DO have rural homes on acreage that could be considered a compound of sorts, I guess, for our own families, if one were really just craving an opportunity to use the term. I, too, hope to have such a place one day, and would want to have dwelling space for each of my kids and their families, so that they had a place to come away and from which to venture out into the world. I'd like it to have a variety of outbuildings for various purposes as well. Would that constitute a compound?
Remember what was written by Mark on one of your other threads? That we're a widely diverse group? We truly are. And while there are many, many books on marriage written by people who not only have devoted their own lives to the subject, but stand on the backs of previous generations of writers (some good and some screwey), there is very little comparative history from which to draw for those of us devoted to forming possibly PM families on a strictly Biblical model. Even the Bible itself seems to have spoken on the most imperative topics but left the rest for us to figure out on our own. Isn't it fun?