Aloysha, safe bed-sharing (non-smoking parents, safe bedding, breastfeeding, no street drugs or medication or alcohol) does not raise the risk of SIDS. The research is pretty clear on this.
The research about dummies and SIDS is poor, and contradictory, but there's no reason not to use dummies alongside established, effective breastfeeding, as long as the dummy is not given instead of responding to feeding needs (that's why Baby Friendly Hospitals don't use them in these very early days). People have differing feelings and preferences about dummies, but no one supporting bf should be telling mothers not to use them if they want to. They should not be saying either as you do that 'of course' a dummy cuts risk of SIDS.
The risks of breast cancer (and other hormone-linked cancers) are reduced but putting a figure on it the way you have is to omit the fact that it's 'dose related' - longer breastfeeding and breastfeeding more than one baby adds to the reduction. Figures differ - my files indicate that 1-2 per cent reduction (your figure) is very much at the lower end of the estimations, but it might apply to 'any' breastfeeding. Just having a baby (below age 35) lowers your risk slightly, of that order, according to some research, but being definitive about any of this is a mistake, IMO, as reproductive and feeding histories are complex.
You say "Given around 15% of women will find it difficult to EBF due producing no milk, or insufficient milk" - No....if you are referring to the Neifert paper, this is not what it shows (as I explained) but if you have another, better example of research to share, please tell me.
You say to me "Tiktok - that's great, so you would tell parents all of that but not tell them why they should look at nappies, poos, wees?! "
I would explain that it's important to check bf is going well, and why, yes. Why would I not? As I explained, I would not say 'your baby is at risk of dehydration if you exclusively breastfeed'. I think it's fine to explain to mothers that assessing breastfeeding (in the ways I outlined) helps them be reassured their baby will grow as he should, will be well fed, and that their milk supply will be robust. If breastfeeding does not appear to be going well, then you would work with the mother to fix it, and say why you are doing it (to make sure the baby stays well, hydrated, with normal blood sugars, jaundice WNL). I certainly would not say 'lets fix this together otherwise your baby will be brain damaged'. There's information sharing, and there is clod-hopping, utterly tactless scare-mongering and shroud-waving.
"Secondly I find it concerning you are saying there are no long term consequences to severe dehydration. That does not jibe with the experiences of many parents, and the studies did not engage in long term followup, so we have no idea." This is misleading....we do have an idea, and there are a number of studies which follow them up (though I have not found a specific UK study). There's a five year study www.ncbi.nlm.nih.gov/pmc/articles/PMC2233705/ which concludes no neurodevelopmental outcomes with 'managed care' ie these babies were properly treated.
Severe dehydration (leading to hypernatraemia) is rare. It should be treated, promptly, in hospital. The short term sequelae (in the UK, where prompt and effective treatment is given) are non-concerning....the babies recover. If it is not treated promptly and effectively, and the baby is allowed to continue losing weight and maintaining high sodium levels, then there are risks...but where in the UK, with normal care, would that happen??