First I don’t have or use whatsapp. But maybe you need the play services to get whatsapp working on LineageOS

ISS detector pro

Fairemail can still not compete with K-9, besides that the premium version cost €7,49 while K-9 is still free

So far so good. Same options as QKSMS. Tried fossify before but that is not even near QKSMS or QuikSMS

None is not right 😋 I have an old Motorola E 2nd gen running an unofficial LineageOS 17 24/7 on external power thaf I use as an automatic phonerecorder on my landline. Battery is not swollen. There are probably more phones who can do this