Firstly you need to remember that Weebly is not the same as either EverWeb or WebAcappella.
Weebly is an online web creation package that is published on the Weebly servers, but I think you can register your own domain name with them if you want to.
EverWeb are both apps that you download and use on your computer and the files are also stored on your computer - not so with weekly. With EverWeb and WebAcappella you need to upload the published files to your server/host, but with Weebly they are already there and with Weebly there won't be as much flexibility with layout - template based, where as with the other 2, you can start from scratch and create anything you like - you can also use a template though.
I have used WebAcappella as well as EverWeb and I have to say that as an alternative WebAcappella is good - I have to say that I quite like it. Might have more of a learning curve coming from iWeb, because it is quite different, but I thought it was good.
As EverWeb has been designed to be like iWeb, then it will be more intuitive - the layout is essentially the same as iWeb, but it might take a little getting used to because you can do so many more things from within the application itself rather than having to look outside it. Things such as the creation of drop down menus, a contact form widget that iWeb did not have, PayPal buttons widget, slide show widget and much more. They have also created Master Pages, etc., but we are still waiting for the Blog to arrive - think they are working on it with the beta versions though.
Persevere with it. Rage has good technical support forums where you can get questions answered and I really don't think that they are likely to go out of business. Remember that Rage Software has been around for a longtime in the first place and gave you the iWeb SEO package that we all used to use with iWeb to give it better ranking. They are a software and hosting company primarily, so I think are very unlikely to go out of business.
If you look at Apple, they are primarily a manufacturer of products, so computers, iPods, iPhones etc., and they are not really into web hosting - it is not what they are best at and I think iWeb, along with firstly .Mac and secondly MobileMe, was their attempt, which they found really did not work, which is why they got out and closed MobileMe and then left iWeb behind, because they realised that other more dedicated hosting and software companies were doing it better than they could. As they have not sold, supported or updated iWeb for at least the last 2 years, I really don't think they are going to resurrect it and update it. That is not really likely to happen when other companies around are doing bigger and better things. They are now playing to their strengths, which is not web design or hosting.
As for the alternatives, I would definitely persevere with EverWeb - it might be worth it in the end and I have designed and uploaded a couple of sites using EverWeb that looked good. They have since gone and been replaced with sites created using Drupal, a Content Management System, because I realised that I needed something that could do more than EverWeb could provide, such as Members Access to the site and other things that are easier to do on a CMS rather than EverWeb, but I was pleased with the site I created and it did not take long and with the help of the EverWeb support forums, you should be able to get all your questions answered.
WebAcappella is definitely worth a look and I think is cheaper than EverWeb - it is different though and you can start from scratch or with a template, but it can produce some very good looking sites. As I say, I have tried it and quite liked it.
You could also take a look at Freeway Pro 7, which is the latest version - that is quite good too.
If you don't want this, then you can try and Content Management Systems instead - these would be Drupal, Joomla and WordPress. All you need is a web host and you should be able to install these with one click directly onto a web host. There are no files stored on your computer at all and it is all done online. All the CMS's are free and open source and they all run on a database. It is a good easy way of getting a website up and running quickly and you don't need to know anything about html, css or php if you don't want to.
You can try out all of the above locally on your computer if you want to by installing MAMP - this stands for MySql, Apache and PHP, which is everything that a CMS needs to run and all you then do is go into the PHPMyAdmin section and create your databases and then download whatever you want to work with, so Drupal, Joomla or WordPress and place the installs in the htdocs file.
If you don't want to try this, then go back and try and persevere with EverWeb and also take a look at both WebAcappella and Freeway Pro7 and see what you think and how you get on.