Are alternate forms of intercourse for a husband and wife safe?

Answer 1

I think you mean "alternative", but what do you mean by "safe"?

In the sense of possible harm or of greater/ less chance of pregnancy?

Really, sexual intercourse is sexual intercourse: the mating act itself. Humans allegedly use a wide variety of different positions, some rather unlikely, to achieve the same result, but none is "safer" than others unless taken to extremes. Biologically, the purpose is to deliver spermatozoa to ova, and the actual form of intercourse does not matter if it fulfils that purpose.

If you don't want the natural result, use contraception.

The golden rule is, love-making should be equally pleasurable and comfortable for both partners. If the form of intercourse being used becomes aesthetically unpleasant, physically uncomfortable or even painful then stop and find a better way. Remembering that pain is a signal that something is wrong, hopefully before any injury occurs.

Note that I have restricted this to copulation, the act that biologically is purely reproductive, not oral or anal activities.