Phaph old leaves long, yellowed and wilting

[Keri_Mar]

I inherited a pahp (Weltz World 'Statuesque' x Rolling Thunder 'Pizzaz') last March. It was in a sorry state with rotted and dead roots in very wet mixture and noticed when I repotted what look like granules of salt (?). I was unable to see an image of what to much fertilization is After several months it finally have sprouted a new growth My question is about the old growth (which have'nt flowered as I don't see any sign of spike) leaves are very long and yellowing with a sunburn. I have since moved the plant to the orig place. Can I cut the leaves leaving about 6-8 inches without compromising the new old at the back? The reason is I want the energy of the plant to focus on the new growth so it will flower and maybe another growth! Or is that too much to ask or does a new growth comes after flowering? I am also propping the old one so it look 'nicer. Is this right? Thanks.