Madeira needs about 5 days and a hire car
Funchal is mild all year; the peaks and north coast are cloudier
Pico do Arieiro to Pico Ruivo: go early, above the cloud
Levada walks follow irrigation channels; many are nearly level
PR trails need a timed booking: €4.50, or €10.50 for PR1
Not a beach island: swim in the Porto Moniz lava rock pools
Keep one spare day for mountain weather; the full guide has the rest