It's easy to manage online presence when you deal with hosting providers, who do take care of their customers. The CP Web Hosting listed companies do provide domain, web space, SSL, and all the resources, which are must for online presence. All get managed by the single company, under one control panel. Isn't easy, to have all hosting needs available from the single provider. Without any hassle, tension, the customer relaxes and concentrates on its core business only. The provider takes care of all the requirements, the business needs for its online presence.
The only question raised is trust one has to build on a single company. But, when it is the branded host which is also an ICANN-accredited domain registrar, this problem, usually doesn't arise.
It is evident that nobody purchases the domain just to forget it. When you buy the domain or transfer the domain to hosting account, you understand your responsibility. Nothing comes for free, if you keep paying the renewal fees, and keep your payment information update, the hosting provider would also, keep things update.
For, renewals the providers often send you to email a month earlier, but again, it is your responsibility to ensure, that it gets renewed on a timely basis. It's simple business, whether you have a domain with a separate company or with the company, you are hosting, if you pay for it, services would be provided. Most often, a customer doesn't pay the invoices on a timely basis, and it may work fine with hosting, but, with domain renewals, it is also advisable to not take such chances and pay invoices on time.
So, it is evident, that, keeping the separate accounts for domain and hosting may be a hassle. If you can trust the provider for hosting, then it can be presumed for the domain also. And, keeping both with the same company, is easy, you log to one account where you can find the invoices for hosting and domain renewals.
Now, there may be cases, which you only wish to keep the domain and cancel the hosting services. For, that you must inform the provider, otherwise, they would continue billing you on a recurring basis.
Typically, most of the companies do offer a certain grace period, but no business likes outstanding invoices. They have right to suspend your hosting services, or if payment not made on a timely basis, they won't renew your domain. The biggest problem with domain renewal is that after expiry time is over, it would go to RGP and client may lose the domain. Such an above case, arises, with customer negligence. And such incidence is not new to this hosting industry.
Hosting companies are also doing business. If your contact email id is updated, then for sure, you might be receiving emails from hosting company. You must always white-list the email ids of hosting provider, as the email generated by them are valuable. Also, a hosting customer must still keep updated with the renewal dates and login to control panel of the hosting provider to make the renewal invoice payments.
There may be a case when you forget to pay for hosting, and now, you are not willing to pay for it, as you don't want it further. It may generate the payment dispute with the provider. Here, the customer responsibility increases, as it is only due to his negligence, the situation gets worsened.
For your online presence, both hosting and domain required, it is up to the customer, to maintain both. Some would prefer to have separate, while some in one account. If it is separate, the customer has to take care of invoices from both companies. While it is from one, then looking invoices at a single place is quite easy.