The client asks about the bar price; the venue has to answer about responsibility

The licence decides, and it is not a preference

Whether alcohol may be served, until when, by whom and in which parts of the premises is set by a licence held in the venue's name, and a breach is the venue's problem rather than the client's. That makes it the one area where "we would normally be flexible" is the wrong sentence. State the terms as terms, say that they are licence conditions rather than house style, and the negotiation stops before it starts.

Corkage is three facts, and venues publish one

Whether outside alcohol is permitted at all, what the charge is and how it is calculated - per bottle, per head, per category - and whether the venue's staff will serve it. Clients hear "corkage allowed" and plan for the cheapest of the possible readings. Publishing the calculation, with an example, prevents the conversation where a client has already bought forty bottles.

Who serves is the question that carries the liability

A client's cousin pouring wine is not the same event as a licensed bartender doing it, and the difference matters to an insurer and to a regulator rather than to a budget. Say plainly what the venue requires: its own staff, a certified supplier from a named list, or self-service within stated limits. This is the part clients find least interesting and the part a venue cannot leave ambiguous.

The end time is a hard stop with a sequence behind it

Last orders, music off, bar closed and guests out are four different times, and a client who hears one assumes the others. Publishing the sequence - and saying which of those times is fixed by licence rather than by preference - converts a midnight argument into a planning decision made weeks earlier.