(a) Any person, eighteen (18) years of age or older, competent to be witness generally in this state may act as attesting witness to a will.
(b) No will is invalidated because attested by an interested witness, but an interested witness, unless the will is also attested by two (2) qualified disinterested witnesses, shall forfeit so much of the provision therein made for him or her as in the aggregate exceeds in value, as of the date of the testator's death, what he or she would have received had the testator died intestate.
(c) No attesting witness is interested unless the will gives to him or her some beneficial interest by way of devise.
(d) An attesting witness, even though interested, may be compelled to testify with respect to the will.