Yes all of those are "allowed" in en_GB. However, the second example you give would almost certainly be rendered as "He'd had problems ...". Yes, really! Thin

Yes all of those are "allowed" in en_GB. However, the second example you give would almost certainly be rendered as "He'd had problems ...". Yes, really! Thinking about it, it depends, for your first example: "Who on earth has three bicycles?" Tom asked, incredulously. "Well, I've got three", replied Jim. "I've three bicycles up for sale today" or "There're three bikes ..." or "There are three bikes". Some people find there're (there are) a bit dodgy. I don't think that en_GB or any other version really gets too hung up on things like that anymore. That said, some constructions do seem more natural than others. I have never heard or seen anyone try to use "have'd" in any modern form of English. You can get "I've had" from "I have had" or "I'd 've had" from "I would have had" or if you really want to drop the aitches then I'd 've 'ad. The last two are quite common in speech but not written.