Hey, Csaba,
glad to hear you’ve sorted out the portfolio page issue.
I will go over your latest questions in the same order:
1). To make the excerpts visible at all times, please try the “Portfolio item captions” drop-down on the “Portfolio Page” tab of the Theme Options panel.
2). The “Portfolio” template does not have a sidebar by design; it should be possible to add a sidebar from inside the “page_portfolio.php” template file, yet one will need to make additional adjustments to the Isotope masonry system in order to display the box grid correctly, and to the content width algorithm, both found in the “header-functions.php” file.
3). If is relatively easy to add a new widget area if you are familiar with php and basic WordPress principles; please see this thread for detailed information.
4). In order to preserve visual identity, all portfolio item boxes are designed to be square in Ikebana. One easy solution to the situation you’ve described is to pre-edit the portrait photos to make them closer to square dimensions (i.e. simple crop in Phtoshop or any other software of your choice).
Sincerely,
Andrii / Satori Studio