Subject: Chemical reaction - Forward and Backward

Can MgO (magnesium oxide) be reduced by H2 (hydrogen)? 
If yes, what are the conditions? i.e. the temperature, pressure, catalyst (if 
any)etc..
Since Mg + H2O --> MgO + H2 - is possible and is sponteneous (if I'm not wrong)
then  MgO + H2 --> Mg + H2O - is also possible (am I right?)

Is this the case with every possible chemical reaction? 
i.e. If a chemical reaction occurs in one direction then it is ALWAYS possible 
to have a chemical reaction in the opposite direction.
E.g. Mg + H2O --> MgO + H2 - if this is possible
then MgO + H2 --> Mg + H2O - is also possible

Re: Chemical reaction - Forward and Backward