Is there anything to setting a high time limit other than more people entering?

If you are that anxious, set the length to 12 hours. That is enough time to let most anyone in all time zones see it. Although usually many people recommend 24-36 hours.
If you are in that of a hurry, 1 hour is the minimum. If you want contributor value, then you either need public and region-free giveaways, or at least 5 participants in a giveaway. Oh, and giving games that weren't free at some point, since they permanently will never give you any CV, ever.

It doesnt contribute anything to your level.
It's highly a personal deal. I like my giveaways to be around a day or two. sometimes going as long as a week.

If you want to give chance to as lot as possible people, then take in mind time zones. If you set it for less then 1 day there could be a good chance it ends when some people have night so they miss it. So a sweet spot could be around 2 - 3 days.

What you should take into consideration though are what level or group you set the giveaway for (it doesnt change anything for your level) but it can change the fact if some bot gets the game just for the +1. If you really want your giveaway to be played I would suggest giving it away in a group that requires that (Playing appreciated for example). Because there are bunch of bots with autojoiners with zero or 1st level. If you set it for level 2 or higher, you do deny access to many no level or 1st level users but you also deny access for bots and +1 collectors who dont care about the win. (I dont doubt there are bots on higher levels, but setting higher levels probably sorts out the best part of them)

In conclusion - it's pretty much up to you. None of these change the CV amount you get.

The popular theory around here is that the longer you make your giveaways, the better the human-to-bot ratio of entrants.
I typically make my public giveaways a day or two long to allow more people to enter. Group or whitelist I make a week or two, same reason.

But, of course, they're your giveaways - feel free to set them as long or as short as you'd like. You get the same contributor value regardless of giveaway length.

Well basically my lower limit is 24 hours. It gives everyone who would've been on in that day the possibility to enter the GA.
No matter how long you put the GA you get the same amount of points as you would a short one (the points only differ if your game has been given away in bundles or discounted)
A week is actually pretty reasonable, as people don't just enter 1 giveaway per day (unless thats all they see that they like) and like me will come back every so often and enter more giveaways. They'll be entertained somewhat without a quick win.

You guys are actually amazing! I'm feeling more confident in setting the time to a week now, it feels pretty fair to everyone! I'll start doing as soon as possible, thank you ♥

You can't do anything wrong either way. Maybe just mix it and do some short and some long running giveaways. You'll soon enough figure out your personal preferences.

I generally set my time to one day because then all people who visit the site daily should be able to see the giveaway and enter.

I often do 1h GAs because I too am anxious and sitting on revealed keys stresses me out. That won't prevent some rude winners to sit on the key for 7 days though... (although that's rare-ish, usually most of my winners confirm their win in less than 24h, and quite often - about half of them I'd say - within a few hours)

But other than that, duration is totally up to you and won't change anything with regards to your contributor level.
However, since you're just starting to make GAs, you only have 3 slots, so if you want to make many GAs you may want to do short ones at first, in order to quickly earn more slots. (you earn 1 slot for every 3 confirmed wins)

I do the Ga's in nearly all cases 3 days long. So none is in a hurry, "all" see them, if they have a stressful day no problem they are able to enter it the next one and they can collect the points to enter if they really want a game i give away :o)

And i would advice you to set a minimum level restriction to hold the most bots and rulebreakers away from your Ga's.
Each that gave 1 game that weren't free is at least level 1.

Its your giveaway so its your rules. I would do at least a day to let everyone worldwide enter but after that it depends on you. If i want to increase the chance so of people winning, i occasionally do snap one hour giveaways but they tend to favour people living in your time zone. I tend to make my giveaways end in the evening so i have time to put the key in after work but you do what works for you. You may want your initial giveaways to finish quicker and therefore hopefully get quicker feedback from the winner as each giveaway that completes allows you an extra slot for making more giveaways. Hope all of this helps a bit and remember to have fun and join a few and maybe win some games too.

Usually I try to make giveaways lasting at least 6 hours and no more than 24.
I have no idea why I am doing this, but I think these are my giveaways and I have the right to set the time that my left heel is saying.
Do not worry about this.

Just because I might visit the site every 59 minutes, doesn't mean everyone does (or can).

So for fairness, my minimum duration for public GAs is 24 hours - it gives time for all those sleepy bots to enter.
However, group and whitelist GAs I usually make for at least a week - a long duration matters less because there's a maximum cap on entrants anyway (i.e. number of people in your whitelist or in the group).

I've done giveaways for an hour, and for a month. No reason, just whatever I feel like.

there are also those that let the duration depend on the quality of the game.
e.g. shorter duration for trashy games - giving those lucky ones to see it a bigger chance. and longer duration for better games - giving more ppl a chance to enter. some do it the other way round.

I prefer short time limit GAs, but when I create a non public one, I give 2-3 days to the members to join. In the beginning I used to create GAs for only an hour, hopeing the winner shal activate it right after it ends.