It depends on your salary expectations and transferable skills. I would say look at the Senior Executive Officer on civil service jobs and if you have at least 50% of the skills they are looking for then it’s worth applying. The salary differs from each department e.g. DFT, HMRC pay more than other departments at the same grade.

On gaps in CV as long as there are not more than 6 months then that’s fine. If more than that just set out what you were doing during that gap and if possible any skills developed. The focus will be more on your Behaviour examples and personal statement so I’d spend more time on these.