I have a possible year of death and NO exact address for my great grandmother. Can anyone here advise me if it would even be worth a try, to
submit an application for a death cetificate ? Thanks!

I don't know if you visited the General Register Office (GRO) Site, but below is a comment from the site regarding sending for death certificates.

'If possible, please give full names of the person whose entry you wish to trace, the most precise date possible and the place where the death took place. Any other identifying information you can supply will also be of help.'

http://www.gro.gov.uk/gro/content/

I applied for 4 certs
3 birth and the 4th a death,

2 births list address as High St, Westbury S
1 birth lists address as High St, East Dean
the death also lists High St, East Dean

these are 4 children born to the same mother

who was actually living at High St Cinderford,
we were hoping to find out at which property.

so the address isnt always as precise as we hope!