(1) This title shall be liberally construed and applied to promote its underlying purposes and policies.

(2) Underlying purposes and policies of this title are:

(a) To simplify, clarify, and modernize the law governing commercial transactions;

(b) To permit the continued expansion of commercial practices through custom, usage, and agreement of the parties;

(c) To make uniform the law among the various jurisdictions.

(3) The effect of provisions of this title may be varied by agreement, except as otherwise provided in this title and except that the obligations of good faith, diligence, reasonableness, and care prescribed by this title may not be disclaimed by agreement but the parties may by agreement determine the standards by which the performance of such obligations is to be measured if such standards are not manifestly unreasonable.

(4) The presence in certain provisions of this title of the words "unless otherwise agreed" or words of similar import does not imply that the effect of other provisions may not be varied by agreement under subsection (3) of this Code section.

(5) In this title unless the context otherwise requires:

(a) Words in the singular number include the plural, and in the plural include the singular;

(b) Words of the masculine gender include the feminine and the neuter, and when the sense so indicates words of the neuter gender may refer to any gender.