the plural of study is studies.
critiques can start with the budget, timescale or availability of subjects for the study, eg. if there were more money and more people ...
critiques can say what went well, and what took too much research time, plus what was unnecessary or over complicated too! if this study were to be replicated HOW would you explain to staff how to mirror the original study?
a good criticism can be 'how' the information was given to participants and whether that material can be improved, eg. were there any non-readers or blind people participating, if so how could they still participate ...
plus all the elements listed by you can be explained and given praise, a neutral response or constructive criticism in your answer ...
good luck x