!firstly:

to kick off

-yes I d say so. To kick off, …

first off

from/at the outset

(to be a tall order=difficult)

!Also:

on top of that,…=in addition

and come to think of it,…

!But

but I must admit/confess,…

but at the same time,…

mind you,…

that said,…

(be a real struggle)

!To be honest:

quite honestly

to be totally up front

(I m not particularly fond of)

!In summary

overall

in a nutshell

basically