Choosing the structure
The three routes have very different consequences, and the decision is usually made too early and too casually.
What diligence should actually cover
Corporate records and the share capital history: defective allotments and unstamped transfers are more common than buyers expect. Title to material assets and property. Material contracts, particularly change-of-control clauses that a share purchase would trigger. Litigation, actual and threatened. Employment and contract labour exposure. Tax and regulatory compliance. Intellectual property ownership, including whether the code and brand are actually owned by the company rather than by a founder.
Diligence findings do not always kill deals. More often they move to the agreement, as a price adjustment, a specific indemnity, or a condition to be satisfied before closing.
The agreement, and the parts that get litigated
Representations and warranties, and the qualifications attached to them. The indemnity: its cap, its floor, its survival period, and whether it is backed by an escrow. Conditions precedent and who bears the risk if they are not met. Non-compete and non-solicit covenants, which must be reasonable to be enforceable.
Closing mechanics deserve more attention than they usually get. Simultaneous versus deferred closing, how the consideration moves, what happens between signing and closing, and the completion deliverables list: disputes here are common and entirely preventable.