Questions about Huawei E5573

I used it with a Swisscom and a Vodafone Portugal SIM card. Both worked, so I would say it is indeed unlocked

Yes, it is possible. No, there are no ethernet ports. You connect via WiFi with the E5573. Here are the instructions: http://download-c1.huawei.com/download/downloadCenter?downloadId=83103&siteCode=lk

I have never used the original cable. Works absolutely without problems.

https://en.m.wikipedia.org/wiki/4G_connectivity_in_Australia. The Huawei E5573 transmits at 800 MHz 900 MHz 1800 MHz 2100 MHz 2600 MHz. I think it is possible. See for yourself under the link a table is available.

The device that was delivered to me has the number E5573Cs-322. There is only one connection (Micro-USB).

Yes, that is possible.

The USB cable for charging is included: https://maxwireless.de/wp-content/uploads/2015/12/Huawei-E5573-Lieferumfang-700x394.jpg

no antennas are included

In principle, it will already work in the USA and Canada. The problem, however, is that the E5573 lacks the LTE frequency bands 12, 13 and 17 - these are the frequencies in the 700 Mhz range. 700 Mhz is used in the USA and Canada for the basic LTE coverage of the large providers in the area, i.e. it is the main frequency. So it might look bad "in the country" with reception if only 700 Mhz LTE is covered with the E5573. In the cities, however, additional frequencies are used which the E5573 supports in order to increase the capacity of the LTE network. So it could be that LTE reception is possible in (larger) cities and not in the countryside - not really ideal. I would make sure to buy a device that supports the 700 Mhz band so that you can be online everywhere. Why not buy it locally together with a sim card?

According to the manual and as I saw it in the configuration menu, this is possible. But I haven't tested it myself yet.

*If* the model designation in the other answer on this product page is still correct (E5573Cs-322, but I can neither confirm nor refute that), then it is quad band (B2/B3/B5/B8 LTE equivalent designation). But is GSM really of interest here? I assume that 3G and/or 4G bands are more likely to be of interest -> it's all here: http://consumer.huawei.com/eg-en/support/mobile-broadband/e5573cs-322/

Yes, it's exactly the same model, I have it myself and it's fine (Salt LTE unfortunately not so much :P)