Dude, its the holidays. People are busy with their family. And I honestly do not foresee this being put closed source any time. There is the whole clause of them legally having to include powered by sugarcrm on the bottom. You are talking about a small team of people developing and giving this away for free and you would like instant free support from a very small niche community.
Honestly my first start would be to go tried and true, that is run on centos6 even centos7 is fine as I run it on there as well. I’m confused I I just installed the latest non beta build of Suitecrm and had no issues.
So lets break everything down to one issue at a time. You have 3. I think the most important is your install, you said it was stuck, and then you mentioned cron and email not working. I would suggest getting your install to go through first, probably could be a source of all your issues since you cannot even complete an install.
As you notice the install according to you stops on the DB steps. You are not using a standard DB in which Sugar/Suite was intended to be used with. That is opensource mysql and now should be mariadb. From my limited understanding not all SQL DB’s are the same as they take different commands and shortucts etc. This could be an issue. I do not understnad why you are using Percona, when a perfectly fine opensource DB can be used that will handle your workload sufficiently. I have an office here of 40+ employees using a single shared server with a single DB on the same server in VPS handling complicated hooks and saves repeatedly non stop everyday, 8 hours a day. I rarely get peformance issues.
Try building a stack from scratch on Centos7.
Now I just realized you said install problem was fixed. OK so i’m fairly certain email is gone through batches from the cron script. I see cron error you get is specific to report generation. Try finding the offending report. There are no reports turned on by default that I am aware of so this is a report you have instituted.
AS far as email not going through, what service are yo uusing for smtp? your own? thirdparty? try to break down the steps the system goes through to send or receive an email and see where it breaks.
If you are running your own email stack, chances are that is the problem as its very difficult to have emails go through with your own stack from experience due to strict spam policies from all major email companies.
MY suggestion is to use a minimal OS, manually install the stack and php modules with mariadb. Correctly add the cron script to correct user. Use a supported DB server. How many clients do you foresee using your system that you believe you need Perconda XtraDB cluster?
And as far as support, i seriously think Ive only seen 2 or 3 official people respond, thats a very small amount of people. You cannot expect them to jump and guide you through an install right before a major Holiday. If you look at my post I only post every couple of months due to me being so busy. The only way for the community to grow is through people contributing the little they can. That includes yourself.