Also- is there a way to test how the survey will appear on smaller screen (i.e. phones, tablets) before I publish it??

Activate it, take the link, test it, deactivate it again if necessary.

Oh- can you still remove/add/alter question types if you deactivate it?

If you deactivate it after activating, the responses are getting archived and you can edit the survey just like before you activated it. Once you have edited you can activate it again. You can do this as often as you want. Just remember that when you deactivate the table with the responses gets archived (not an issue when you just test, but when you need to do this after already receiving real responses). But this is also no big deal. If you have to deactivate a survey that is already in field, I would always first export the responses, just to have them as CSV or XLS so you don't lose them if something should unexpectedly go wrong. Once you reactivate, Limesurvey will offer you the option to "rescue" the archived responses and in most cases this works well.

To answer this

it's very important that people who do not consent (i.e., select 'no') not be shown any more of the study, barring the final debriefing message that thanks participants for their time. How would I set this up?

Use a quota with limit 0.
Meaning 0 persons who answer "no" are allowed to proceed.
And there you enter a message for them.

Thank you.

I have a question about the 'code' names for array questions. I have several array questions within my survey that are structured identically, but ask about a different stimuli each time. That is, they need to have their own designated column within the data spread sheet when I export the results. Is it necessary to provide an individualized answer code for each and every array answer option, across all repetitions of the arrays? My question codes are already individualized but I'm just worried that all the data will be amalgamated together when I down load the results....

Question and sub-question codes must be unique as they define data column names. Answer codes don't need to be unique as they are the data content.

Always test your survey, downloading the data to ensure that you are getting what you expected.

sI'm struggling a little; is there a quota option for individual questions? I can only find a 'survey quota' option..

 and sub-question codes must be unique

To clarify: subquestion codes must be unique within one qiestion.
No problem to code
Question Q1 with "SQ001", "SQ002",... and
Question Q1 with "SQ001", "SQ002",...

The database columns will be "Q1_SQ001", "Q1_SQ002",..., "Q2_SQ001"

But as @tpartner.
Such things you have to try

Joffm

Thank you! I will test everything once I figure out the quota issue...

www.limesurvey.org/manual/Survey_quotas