Re: mastic gum and mag-malate

 I ordered both the mastic and mag-malate.The supplement facts for the mastic gum says other ingredients are hyrdo oxproply methylcellulose,cellulose,magnesium sterate, silicon dioxide are these ok?

These are binders and flow agents so it sounds like a tablet.  You will find similar ingredients in most tablets.  Capsules will sometimes use flow agents, but they have less added ingredients than capsules.  If I had to choose between tablets or capsules for this reason I would go with capsules.

Finally the mag-malate has 100 mg of magnesium(as magnesium amino acid chelate) and 400 of malic acid, is this sufficient?

If you are going for ATP formation yes as both produce ATP.  You will also be getting more magnesium from your diet, especially dark green leafy vegetables.

The mag-malate is from Douglas Laboratories and the mastic gum is from Nutri-Cology. Are they both ok to use?

Yes, the flow agents and binders are generally safe in the small amounts you would be ingesting.