There is no inclination of actors just being so stupid as to gain 40 pounds so they cannot work or fit into a fitted costume. Common sense should dictation they need to maintain their weight. Now, it will be in future actor contracts to do so. That's another reason I'm going union, for a smarter breed of actors.
SAG would be over actors with attendance like white over rice because SAG gets paid and they in turn pay the actors. I've known SAG actors to lose their union cards for pulling stunts that these nonunion divas get away with.
I pulled one of my better actresses aside for being a few hours late to tell her Steven Spielberg fired Megan Fox for lateness and spending too much time on her cell phone like my actress was doing.
Small production have no backup funding. That's the reality of life. This year, two rain days killed my pockets for pickup footage.
I don't think that going union will solve the problems you are having.
I'm all for SAG, but there are plenty of unprofessional union actors around as well.
I know some won't like what I have to say, but personally I wouldn't deal with SAG unless you are going after "names" or you're working with a bigger budget.
You are financing this out of pocket and shooting with no-name actors, becoming a SAG signatory production would just be another hassle that I don't think you need.
And chances are the union actors you would be hiring under the SAG agreement would probably work on a non-union shoot as well.
Many experienced union actors, even bigger name actors work non-union all the time.
And just to be clear, SAG doesn't pay your actors, you pay them, SAG will want a deposit, after you've wrapped and they've confirmed that everyone's gotten paid you will get the deposit back.
So you not only have to pay your cast members, you have to pay SAG as well, even though you'll get the deposit back, you still have to budget that in.
Allthough I know some who have negotiated themselves out of paying any deposits with SAG, it's always negotiable.
Regarding Megan Fox, I believe the story goes that she got fired by Spielberg because of her antisemitic statements, but who knows what the truth was.
Regarding backup funding, that's what a contingency is for. Every production, no matter how small, should have a minimum 10% contingency in their budgets.
I really am sorry to read about your problems with this production.
When you hired your crew, did you ask for referrals?
Instead of posting wanted ads for crew members, have you tried to contact filmmakers and production companies near your area and ask them if they can recommend anyone for you?
Whoever you hire, always try and talk to a producer or a director they've worked with in the past who can tell you how that person was to work with.