Like Veg, I prefer to eat differently, rather than rely on substitutes. I've never enjoyed milk on muesli / cereal / oats but always used a good fruit juice instead (current favourite is pressed apple & mango).
Kombucha is supposed to be a really good probiotic that you can make yourself. I am about to try this so I'll be able to report backroad the forum in a few weeks.
As a spread on bread, extra virgin olive oil is good (that's what they use all over the Mediterranean) but as Veg says, if the ultimate topping is moist (hummus, Baba Ganoush / jam, marmalade) you might need nothing at all?
As for a whitener for coffee, like you, I struggled a bit to find one I could cope with. I've settled on Alpro's Simply Mild which is soya based but much more acceptable to my tastebuds than the regular soya milk. Might it be worth experimenting with different brands, or variations within brands. As as last resort, I suppose we could wean ourselves onto black coffee? II'll sometimes opt for a ginger tea instead - it gives a lovely warm 'kick' and does not have the same liberating effect on my bladder that coffee can do!
I had a great craving for treats and sweet things when I first started OMS, and got through an unconscionable quantity of dates. I baked small mountains of amaretti (good recipe in Antonio & Pricilla Carluccio "Complete Italian Food" and huge fluffy meringues (there's a brilliant recipe for cinnamon and hazelnut meringues made with muscovado sugar in Ottolenghi: The Cookbook) I made Panforte (Italian Christmas treat stuffed full of nuts and dried fruit that I could happily eat all year round), a million times better home-made than shop-bought, again from the Carluccio book.
For desserts, consider sorbet, or a fruit salad served with a couple of fresh amaretti on the side. Drizzle a bit of liqueur over the amaretti to make them even more delicious. I seem to remember there being a recipe for a meringue roulade on the Ottolenghi site. The recipe, I think, suggests a dairy filling but I remember musing that I might try it with a filling of chestnut purÃ©e and slightly squashed raspberries.
A site run by an OMS team member has a recipe for some delicious sounding granola bars that I have been meaning to try - https://laughinglemon.ch/category/recip ... ergy-bars/
The same site has a recipe for a chocolate chip olive oil cookie that I am sure would be just as good with dried cherries plumped up in lemon juice and perhaps some ground almonds instead of the chocolate:https://laughinglemon.ch/chocolate-chip ... l-cookies/
You might also like to have a look at http://www.henriettainman.com/
She is a trained pastry chef who has recently published a cookbook called 'Clean Cakes' with all sorts of delicious-looking things in it - all dairy and gluten free. The one problem with Clean Cakes from an OMS point of view is that Henrietta does use a great many coconut products - and coconut is a no-go area on an OMS diet. Substituting coconut oil is tricky as she uses it because it sets solid at room temperature, which is precisely why we don't have it! Although this means there are recipes in the book I won't be using I still think it has a lot to offer in terms of inspiration for a life without dairy!
Filo pastry is made with olive oil (it's not hard to make your own, and thus ensure that the oil is EVOO) so that's a good substitute for puff pastry. So you could make strudel? If you really wanted to go to town, you could make your own honey & pistachio baklava!
Listing all these goodies quite makes me want whip out my apron and get baking, but generally I have found the craving for sweet things to have largely disappeared over recent months. Perhaps because the OMS diet has had a positive effect on the fatigue - with fewer energy dips, the urge for treats has diminished?
If cheese is high on the list of things you miss, you might like to check back in the diet forum for a post called "Cheese . . . I miss cheese'. It contains links to nut based alternatives that are OMS compliant (a lot are not) as well as to recipes for vegan cheeses and yoghurts.
PS if you'd like the recipes mentioned above, and can't lay your hands on the books, send me a private message with your email address and I'll send you a scan of the relevant pages.