In a word, YES! Here are your options.

Connect PC via HDMI - however, the max resolution the DAC on that receiver can handle is 24bit/96khz where many HD files are 24bit/192khz. It should downsample to 96khz and still play. Additionally, it will not accept a FLAC, ALAC or even an AAC file directly so you will need to convert from purchased format to an LPCM signal on your PC.

Burn SACDs - assuming you have the software to support the burning, but you will need to ensure that you are outputting an LPCM signal from the Blu-ray player. This is the default on most BluRay players so unless you changed a setting , that is the signal it should be sending. You can check this quickly by playing a Dolby TrueHD disc. The Dolby TrueHD light should not light up on your receiver and it should display 5.1 channels stereo or something of that sort.

Burn DVDs or BluRays in decodable format - This eliminates the need to create SACD discs specifically. You could also buy or convert files to a lossless format that the BluRay player supports directly. It doesn't support FLAC or ALAC but it looks like it will support WMA9 or 320K AAC files.

Stream to BluRay via your network - The BluRay player is a DLNA Client so if your files are in a decodable format and the player is connected to your network, you could use it as a media renderer. This is the best method IMO largely because it allows you to access your whole music library on your computer and play what you want when you want and eliminates the need to have your PC close to your receiver or the effort involved in burning discs.

The weakest link is your receiver in terms of sound quality. It has a bad internal DAC and a few reviews I found said it was not the best sounding relative to its peers. A newer network receiver with a strong internal DAC that supports FLAC for instance, would probably make your life infinitely easier.

That is an extremely low-quality receiver, in both features and sound quality.

There is not much point in playing high-quality music of any kind through it, because it will sound terrible!

It is also NOT a networking receiver; it will only do a sort of limited networking IF you interface it with Sony proprietary S-Air devices.

Amazon has limited quantities of the Denon AVR-E400 receiver for only $420; that is a very good receiver at a good price. Go for it.