grub2 - Old partition to create new partition - Ask Ubuntu

a few years ago started using ubuntu because somehow computer unable work windows. ubuntu worked since then, except today. today turned on computer , had problem:

boot: run-init: /sbin/init: no such file or directory 

since have of data backed , in reality hadn't installed relevant programs on computer, decided avoid problems , reinstall ubuntu. expecting of files erased, turns out in different partition/drive size of 700gb, , "home" partition size of 46gb. don't ask me why, click ok in everything.

i think 46 way little, increase size of it, have lot of space in 700gb. however, every time try resize 700gb, gparted says dangerous, don't know do. had impression 700gb partition on past , contained no system files. question is: can resize partition of 700gb without screwing grub , have reinstall it? ask because sounds difficult reinstall grub , in reality newbie have ubuntu because works computer.

is there way use 700gb partition "home" partition install programs , everything?

side note: don't use windows @ in computer, got screwed , never ever worked again (i think deleted create 700gb partition).

thank you!

here picture:

the sda4 partition (~46gb) /(root).

the sda7 (~700gb) not /home (/home under /) , it's not in use installed ubuntu; maybe leftover previous installation.

and still have ntfs (windows) partitions there.

whatever decide do, do not touch sda2 (efi partition).

that said, can remove ntfs partitions if don't need windows. then, in order maximize resources in sane way, here few suggestions:

• having swap partition of +130gb huge waste of space. +8gb ram barely need 2gb! right-click , swapoff resize accordingly , move right.
• backup sda7's contents if applicable , remove partition altogether.
• resize sda4 in order use remaining unallocated space.

notes: above suggestions assume deleted ntfs parttions. need use gparted in live session. partitions cannot "in use" (mounted) operations. in live session swap used hence need swapoff. finally, there's no point in removing sda1 base there's little gain in terms of space , shouldn't moving efi partition anyway (and make use of space need move other partitions left increased risk of data loss).