Hello there,
I’m Ben one of the 4 guys behind wysija.
1/By professional you mean corporate style ? Can you be specific on those issues you’re having with wysija maybe we can improve that in a future release.
Otherwise everything seems possible with wysija apart from the fifth point, not being flagged as a spam. Though we wrote a little guide to help you avoid that, those are good guidelines you should follow : https://support.wysija.com/knowledgebase/6-golden-rules-to-avoid-being-labeled-a-spammer/
The advantages of wysija over MC are that :
1/you manage your newsletters straight from your WordPress panel.
2/In the future Wysija will integrate better with third party plugins while it will be difficult with external service such as MC
3/it is either free(less than 2000 subscribers) or cheaper to send with wysija.
Read this little case study explaining why one of our users preferred wysija over “the big boys” (MC, Aweber, etc..)
https://www.wysija.com/wordpress-members-newsletter-case-study/
Hope this helps you in your decision, and let us know about those issues you’re having on https://support.wysija.com !
Cheers
Ben