I haven't read the whole thread, but this resonated with me so wanted to respond.
If you both see a future together (marriage, kids etc) it shouldn't matter if one of you earns more than the other. You can get a joint mortgage. My now DH and I did before we were married with him earning a lot more than I did, and it wasn't an issue as we knew we would get married at some point and have a family together. Basically we knew we were in it for the long haul so it didn't matter.
If your boyfriend is suggesting he simply buys a house himself and you pay towards bills etc and you're happy with that, then that's fine. If you're wanting to get a mortgage together wi TY both of your names on the house (regardless of how much you earn), and he's saying no, 'I want the mortgage in my name only and you to chip in', and you're not happy with that, then that should be a massive red flag for you in terms of how committed he is to you and your relationship.
Personally, from experience I wouldn't go down the 'paying lodger' route. My ex boyfriend always said to me that because he made so much more money than me he would buy a house himself and I'd have to pay 'rent'; it wasn't a consideration for him to buy a house together. Whilst at the time I didn't consider buying a house with him because our relationship was in such a dire state anyway, it only highlighted to me that he didn't see me as equal to him because I didn't make as much money as he did, even though I always paid 50/50 towards the rent and all the bills.
If you're not happy with what he's suggesting have a frank and open conversation about it, and if you're still not happy, follow your gut instinct.