No problem
@Affable Bear ! Happy to help.
I met my husband when I was 29 and he was 34 so similar ages to you both now (he was good with money so i credit the 19 years we've been together as my journey from zero to FIRE). We just hit our FIRE number this year so I can wave from the other end and say a) it's definitely worth it and b) you've already been at it for four years so you're in a great place!
You're asking a lot of the questions we had too (and similar fears about the government changing goalposts etc). Like you, we wanted maximum freedom and flexibility but after doing some research found in our case, adding to SIPPs too was still worth doing so it's always worth keeping an eye on things. I think we had to get over the feeling, to some degree, that we were locking money away till certain ages but realised there are sometimes enough benefits to doing that at times.
I dug around in the helpful advice I got earlier on our own journey from the folk on the UK board and found this link to a series of articles on the tricky ISA & Pension balancing act that addresses what you're pondering...
https://monevator.com/tag/ISA-pension-split-series/Re LISAs it looks like you can still have a lifetime ISA even though you've had a help to buy...
https://www.ajbell.co.uk/faq/can-i-have-both-help-buy-isa-and-lifetime-isaA couple of other thoughts...
Mortgage? We paid off our mortgage in 8 years. We then redirected the overpayments to FI lump sum. Not for everyone but worked well for us. Worth crunching the numbers vs other investments.
A small but useful benefit we found was the couples tax allowance and spreading tax (might be useful if you decide to have kids and one of you earns less than £11,500 at that time -- for e.g.).
Sometimes there's different options and tax benefits in how you can invest in your workplace pension, contribute more etc so that could be worth investigating as well as SIPPs. Your workplace can usually inform you of options.
The benefits of nipping any lifestyle creep (without feeling poor) and the power of compound interest.
We're still tinkering with things ourselves. Even though we're closer to private pension age than you guys, we're still wary of having too much in SIPPs vs ISAs and potential government shenanigans! I'm getting more confident in my financial knowledge , lol.. but do recommend picking the UK boards collective brain too! they're great and often will know more of the ins and outs .. that's where we've learnt what we've needed so far.