Okay, from what you've said that your server is currently at v.2.0, then i don't know what kind of features or whatever your server have but i'm going to give my opinion about this level freezing ..

First of all, i believe that level freezing is for those people who can support their ninjas, and what i mean by support is to spend even a little to support his/her needs .. Because Freezing means to avoid the events that can give you experience .. Avoiding to claim any froggies in your Daily Missions results to not having bonus items like the Myoboku Gifts, Summoning Scroll Fragments, Main Character Fragments and etc .. The Nine Tails Invasion, this event can give you massive amount of experience so you need to avoid this and by avoiding this, you will automatically lose Magatama and Coupons .. Rescue the Jinchuriki event also gives exp, Sweeping Plot/Elite Instances, Ninja Test, Ninja Exams, Wanted Missions and other events and missions .. You will be forced to pick and choose what event or mission you will only do ..

By that way, alot of items/bonus items will be not claimed and that means also less power and resources such as coupons and coins .. To be able to catch up with that loss, you must spend atleast a little to buy some items to get power ..

Nine Tails Invasion = The more Damage you do, the more exp/coins you get .. Even just 1 round, you can automatically get big chunk of exp ..

If you wanna freeze level to max then you need to take the consequences of doing that, unless you're one of the guys that can spend atleast 100$ a month .. But you c*so freeze a little, by just choosing what events and missions you're gonna do and take part .. I never chose this path since i'm a full f2p and i only rely on events and missions to get power-up items and resources for my ninjas ..

As a member of a group, you must claim the first froggy which gives 6 Group Chakra Packs, as time goes, chakras will be a problem for a group ..