I don’t have it as I went for the literal bag of primes (16, 23, 35 & 50) but the XF 16-55 f2.8 is well regarded as a “bagful of primes”. 16mm is a 24mm equivalent on the wide end and 55mm is close to an 85mm equivalent. F2.8 gives a good level subject separation/bokeh. Not small or light but plenty of folks sing it’s praises.
Not really, unless you want to limit yourself a lot on the image quality.
For portraits I would recommend at least an 85mm F/1.4 lens. For landscape photography it depends on whether you want to make panoramas and then the question is which focal length or image effect you want to achieve. There is a lack of more precise information on your part.